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SEA - ONT

$49 Find cheap flights from Seattle to Ontario

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Seattle to Ontario departing on 6/18. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
0 bags
Mon 6/3
Mon 6/10

Search hundreds of travel sites at once for deals on flights to Ontario

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Seattle to Ontario.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Seattle to Ontario.
In the last 7 days travelers have searched 43,693,958 times on KAYAK, and here is why:

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Cheap flight deals from Seattle to Ontario (SEA-ONT)

Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Seattle to Ontario that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices and deals for you by selecting your travel dates.
Choose your dates
1:57 pm - 4:41 pmSEA-ONT
2h 44mnonstop
10:04 am - 12:57 pmONT-SEA
2h 53mnonstop
$52Frontier
Find Deal
Wed, May 22 - Wed, May 29
1:57 pm - 4:41 pmSEA-ONT
2h 44mnonstop
10:04 am - 12:57 pmONT-SEA
2h 53mnonstop
$53Frontier
Find Deal
Wed, May 22 - Wed, May 29
1:57 pm - 4:41 pmSEA-ONT
2h 44mnonstop
9:54 am - 12:47 pmONT-SEA
2h 53mnonstop
$55Frontier
Find Deal
Wed, May 22 - Tue, Jun 11
1:57 pm - 4:41 pmSEA-ONT
2h 44mnonstop
10:04 am - 12:57 pmONT-SEA
2h 53mnonstop
$58Frontier
Find Deal
Sat, Jun 1 - Tue, Jun 4
1:57 pm - 4:41 pmSEA-ONT
2h 44mnonstop
10:34 am - 1:27 pmONT-SEA
2h 53mnonstop
$62Frontier
Find Deal
Wed, May 22 - Thu, May 30
1:57 pm - 4:41 pmSEA-ONT
2h 44mnonstop
11:43 am - 2:36 pmONT-SEA
2h 53mnonstop
$63Frontier
Find Deal
Sat, Jun 1 - Sat, Jun 8
3:23 pm - 6:01 pmSEA-ONT
2h 38mnonstop
5:00 pm - 11:59 pmONT-SEA
6h 59m1 stop
$166Delta
Find Deal
Wed, Jun 5 - Wed, Jun 12
2:17 pm - 5:01 pmSEA-ONT
2h 44mnonstop
8:09 pm - 10:50 pmONT-SEA
2h 41mnonstop
Fri, May 24 - Wed, May 29
9:26 pm - 11:59 pmSEA-ONT
2h 33mnonstop
10:06 am - 12:53 pmONT-SEA
2h 47mnonstop
Mon, Aug 12 - Mon, Aug 19
5:00 am - 11:44 amSEA-ONT
6h 44m1 stop
4:45 pm - 11:59 pmONT-SEA
7h 14m1 stop
$206American Airlines
Find Deal
Tue, Oct 15 - Wed, Oct 23

Flights from Seattle to Ontario - Travel Insights & Trends

Get data-powered insights and trends into flights from Seattle to Ontario to help you find the cheapest flights, the best time to fly and much more.

What’s the cheapest day of the week to fly from Seattle to Ontario?

The average price of all flights from Seattle to Ontario clicked on KAYAK for each day over the last 12 months.
If you are looking for a flight deal from Seattle to Ontario, look for departures on Wednesdays and avoid leaving on a Sunday, as it's usually the priciest day. When flying back from Ontario, Wednesday is the cheapest day to fly and Sunday is the most expensive.

What is the cheapest month to fly from Seattle to Ontario?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for flights from Seattle to Ontario, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.
The cheapest month for flights from Seattle to Ontario is September, where tickets cost $168 on average. On the other hand, the most expensive months are December and April, where the average cost of tickets is $273 and $260 respectively.

How far in advance should I book a flight from Seattle to Ontario?

To calculate daily average prices, KAYAK takes all prices for each day before departure over the last year for flights from Seattle to Ontario, removes the top 0.1% to account for outliers, and then takes the average of all the values for each month.
To get a below average price on the flight from Seattle to Ontario, you should book around 2 weeks before departure. For the absolute cheapest price, our data suggests you should book 65 days before departure.

Which airlines provide the cheapest flights from Seattle to Ontario?

The cheapest price for the route for each airline clicked by KAYAK users in the last 72 hours.
The cheapest return flight ticket from Seattle to Ontario found by KAYAK users in the last 72 hours was for $52 on Frontier, followed by Delta ($166). One-way flight deals have also been found from as low as $49 on Frontier and from $88 on Delta.

Which airlines fly most frequently between Seattle and Ontario?

Alaska Airlines connects Seattle to Ontario with up to 4 flights per day. Delta also offers 4 flights per day, while Frontier follows with 1 flight per day.

Which airlines fly non-stop between Seattle and Ontario?

Airline and price data is aggregated from results in KAYAK’s search results from the last 2 weeks for flights from Seattle to Ontario.
There are 3 airlines that fly nonstop from Seattle to Ontario. They are: Alaska Airlines, Delta and Frontier. The cheapest price of all airlines flying this route was found with Frontier at $56 for a one-way flight. On average, the best prices for this route can be found at Frontier.

How many flights are there between Seattle and Ontario per day?

Each day, there are between 9 and 11 nonstop flights that take off from Seattle and land in Ontario, with an average flight time of 2h 36m. The most common departure time is 7:00 am and most flights take off in the morning. Each week, there are 69 flights. The most frequent day of departure is Wednesday, when 16% of all weekly flights depart. The fewest flights depart on a Friday.

Which cabin class options are there for flights between Seattle and Ontario?

The average price of flights for each cabin class for the route found by users searching on KAYAK over the last 2 weeks.
There are 4 cabin class options for the route. These are First, Business, Economy and Prem Economy. Perform a search on KAYAK to find the latest prices and availability for all cabin fares, which differ across airlines.

How long does a flight from Seattle to Ontario take?

Direct flights cover the 956 miles separating Seattle to Ontario in about 2h 30m.

What’s the earliest departure time from Seattle to Ontario?

Early birds can take the earliest flight from Seattle at 6:32 am and will be landing in Ontario at 9:05 am.

What’s the latest departure time from Seattle to Ontario?

If you prefer to fly at night, the latest flight from Seattle to Ontario jets off at 9:26 pm and lands at 11:59 pm.

Good to know

Low season

January

High season

June

Cheapest flight

$49
Best time to beat the crowds with an average 9% drop in price.
Most popular time to fly and prices are also 7% lower on average.
Flight from Seattle to Ontario

When to book flights from Seattle to Ontario

Are your dates flexible? Find out the best times to travel from Seattle to Ontario based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from Seattle to Ontario

  • Does SEA have facilities for disabled traveling passengers?

    You can use the sunflower lanyard program when you're departing from Seattle to Ontario and need assistance at the SEA airport. This program is available to passengers with hidden disabilities who need extra help with check-ins, security screening, and carrying luggage. If you'd like to use the service, you can request sunflower lanyards at the pre-security information desk, between checkpoints 3 and 4, or the post-security information desk in Concourse A.

  • Does Ontario Airport have pet relief areas?

    Once you land in Ontario, you can use the pet relief areas inside and outside the terminals if your pet needs relief. The outside areas are at the far end of the terminal buildings. The areas inside are near gates 210 and 410. The relief areas have waste disposal bags and bins, which you can use to clean after your pet.

  • Is there public transportation available from Ontario Airport?

    Ontario has a well-designed bus and rail transportation service. If you'd like public transport from ONT, you can use the public buses boarded at terminal 2. The buses are available every 20min.

  • Does Ontario Airport have a USO Military Lounge?

    The USO military lounge is a space for military members and their families to sit and relax. Families can access free internet services, entertainment, and food and drinks. The ONT USO lounge is across parking lot F.

  • What is the cheapest flight from Seattle to Ontario?

    In the last 3 days, the lowest price for a flight from Seattle to Ontario was $49 for a one-way ticket and $52 for a round-trip.

  • Do I need a passport to fly between Seattle and Ontario?

    No

  • Which airlines offer Wi-Fi service onboard planes from Seattle to Ontario?

    Alaska Airlines, Delta, American Airlines, and JetBlue offer inflight Wi-Fi service on the Seattle to Ontario flight route.

  • Which aircraft models fly most regularly from Seattle to Ontario?

    The Boeing 737-800 Passenger/BBJ2 (winglets) is the aircraft model that flies most regularly on the Seattle to Ontario flight route.

  • Which airline alliances offer flights from Seattle to Ontario?

    oneworld, and SkyTeam are the airline alliances operating flights between Seattle and Ontario, with SkyTeam being the most commonly used for this route.

  • On which days can I fly direct from Seattle to Ontario?

    There are nonstop flights from Seattle to Ontario on a daily basis.

  • Which is the best airline for flights from Seattle to Ontario, Alaska Airlines or Delta?

    The two airlines most popular with KAYAK users for flights from Seattle to Ontario are Alaska Airlines and Delta. With an average price for the route of $228 and an overall rating of 8.0, Alaska Airlines is the most popular choice. Delta is also a great choice for the route, with an average price of $218 and an overall rating of 8.0.

  • How does KAYAK find such low prices on flights from Seattle to Ontario?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Seattle to Ontario.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Seattle to Ontario?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Ontario from Seattle is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Seattle to Ontario?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Ontario with an airline and back to Seattle with another airline. Booking your flights between Seattle and ONT can sometimes prove cheaper using this method.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Seattle to Ontario?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Ontario from Seattle up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

See more FAQs

Top tips for finding a cheap flight from SEA to Ontario

  • Looking for a cheap flight? 25% of our users found flights on this route for $78 or less one-way and $118 or less round-trip.
  • Seattle Airport (SEA) has made it easy for travelers departing from the airport and are interested in parking their cars. The airport has a pre-booking system that allows travelers to book a parking spot before arriving at the airport. You can use this feature through the airport's website.
  • When departing to Ontario from Seattle Airport, saving time at TSA screening is a priority. Fortunately, SEA has a service that allows passengers to reserve a screening spot through the SEA Spot Saver. Reservations and walk-in appointments for departing passengers are available from 5 am to 1 pm every day at checkpoints 2, 3, and 5 for all airlines.
  • There are various transport options when you land at Ontario Airport (ONT). You can pick up a rental car from the rental car facility. ONT has airport shuttles that ferry passengers from the terminals to the on-airport rental car center. The shuttles run every 5-20min and are at the Terminal Islands of terminals 2 and 4.
  • Waiting for your flight to Ontario at the Seattle Airport can be overwhelming. You can stay in the sensory room if you need a calming environment to minimize anxiety. The room is at the train level of the A gates STS Station.
  • Every day, people face life challenges. The busyness at the airport, waiting for a flight, going through security, and checking in can add to the stress. Seattle Airport has realized this and has a beautiful therapy dogs service. The airport has partnered with Pet Partners program, where Pet Partners and their trained animals offer animal therapy at the airport. A friendly dog face or hug goes a long way to reducing stress.
See more tips

Prefer to fly non-stop from Seattle to Ontario?

Find which airlines fly direct from Seattle/Tacoma Intl to Ontario, which days they fly and book direct flights.

Nonstop departures

Seattle/Tacoma Intl to Ontario

Monday

Alaska Airlines, Delta, Frontier, +6 more

Alaska Airlines, Delta, +7 more

Tuesday

Alaska Airlines, Delta, Frontier, +6 more

Alaska Airlines, Delta, +7 more

Wednesday

Alaska Airlines, Delta, Frontier, +6 more

Alaska Airlines, Delta, +7 more

Thursday

Alaska Airlines, Delta, Frontier, +6 more

Alaska Airlines, Delta, +7 more

Friday

Alaska Airlines, Delta, Frontier, +6 more

Alaska Airlines, Delta, +7 more

Saturday

Alaska Airlines, Delta, Frontier, +6 more

Alaska Airlines, Delta, +7 more

Sunday

Alaska Airlines, Delta, Frontier, +6 more

Alaska Airlines, Delta, +7 more

See more direct flights

Nonstop returns

Ontario to Seattle/Tacoma Intl

Monday

Alaska Airlines, Delta, Frontier, +6 more

Alaska Airlines, Delta, +7 more

Tuesday

Alaska Airlines, Delta, Frontier, +6 more

Alaska Airlines, Delta, +7 more

Wednesday

Alaska Airlines, Delta, Frontier, +6 more

Alaska Airlines, Delta, +7 more

Thursday

Alaska Airlines, Delta, Frontier, +6 more

Alaska Airlines, Delta, +7 more

Friday

Alaska Airlines, Delta, Frontier, +6 more

Alaska Airlines, Delta, +7 more

Saturday

Alaska Airlines, Delta, Frontier, +6 more

Alaska Airlines, Delta, +7 more

Sunday

Alaska Airlines, Delta, Frontier, +6 more

Alaska Airlines, Delta, +7 more

See more direct flights
See more direct flights

Top 5 airlines serving from Seattle to Ontario

 
See real verified KAYAK customer reviews for airlines flying from Seattle to Ontario. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Seattle to Ontario? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
Alaska AirlinesOverall score based on 9128 reviews
8.6Crew
7.3Entertainment
8.2Boarding
7.3Food
7.9Comfort
Airline reviews

My baggage was in another flight, anit was delayed for one hour.

4.0 OkayAnonymous, May 2024SEA - LAX
Read more about Alaska Airlines reviews

My baggage was in another flight, anit was delayed for one hour.

Up on arrival, due to twisted ankle, I wasn’t able to walk. Requested for a wheelchair. They immediately asked for it. After 10 minutes wait a young man named Carlos picked me up at the gate, got my baggage and took me to the pick up area. It was a great service. Thanks Alaska Air line

Good. Quiet. Comfortable. The protests nearly kept me from catching my flight. They waited for me! I made it!

I tried to cancel my flight weeks in advance round trip and told I was not able to. $400 down the drain

wish Airlines would board the plane starting in the back first. Makes more sense and I think it would be faster, NO? Everything else was great!

I went Premium otherwise it would have been a long wait. On board I only asked for a cup of hot water and got lukewarm. Cabin crew have poor to no service. But great flight; it went smooth.

I appreciated the check-in at SEATAC - a knowledgeable person was available. I found it easy to ask questions as I went along. I hadn't been at SEATAC for a year and was not that familiar. Parking was fine at Sacramento

My baggage arrived at the airport on an earlier flight. It would have been nice if I would have gotten a text. I waited until all the luggage had arrived before Ivwent to the baggage counter!

I had to check-in my small carry-on at the gate which was inconvenient. According to the people at the gate at SEATAC, there wasn't anymore room in the overhead bins. I obliged. But, when I got inside the aircraft, there was plenty of room EVERYWHERE! It was either miscommunication or incompetence among the Alaska personnel.

Bad. The fight was late and they gave a ridiculous $12 stipend. Better give something or nothing. $12 is ridiculous.

Had a broken tray in business class. Crew just shrugged it off.

Everything was great except for the seat. The backrest would not stay in the upright position.

public website still broken for years randomly blocking browsers with privacy options active after loading a page maybe once. check-in on laptop was almost impossible but eventually randomly worked. had to print pass at airport since couldn't get back in to load digital pass on mobile firefox or chrome. red eye flight so smooth onboarding, plenty of room to spread out, easy offboarding. onboard wifi instructions mention vpn can cause problems connecting but fails to also mention private dns. no printed or built in menu list, seems weird to require personal device to point at qr code link for menu which does not even allow direct ordering. people with health condition risk related dietary restrictions trying to avoid for example cholesterol and sugar are left guessing what they can order either way without nutritional info highlights (cranberry juice was minute maid cocktail with as much suger as typical can of soda). tap to pay wasn't working and always seems sketchy to manually enter card info. good movie variety, so limited tv was okay.

Bag drop off was slow and annoying. Only 2 agents at the entire delta desk, and no one directing traffic for what line to be in, many confused people slowed down the process. Boarding was fine. Seats in Delta comfort plus were fine. Snacks were great! Definitely a bonus. The entertainment system was awful — old, slow, not responsive, and completely unable to play games due to some kind of error. But on the other hand, thank you to Delta for the free WiFi. That made it better.

Flight diverted in SD. Later take off in Seattle by 1.3hrs

Mi primera conexión se retrasó por lo cual perdí mi segunda conexión la cual salió adelantada

Crew was not friendly when I went to request a seat change.

There were choices for the snacks. Good choices and tasty lunch and breakfast as well.

The flight crew was amazing. I’m very tall and they moved me to an exit row unsolicited!!! Amazing service.

The boarding process was terrible especially with an indirect flight Chicago to Seattle to San Diego was terrible talking about we overbooked a flight idk if I’d take this airline ever again we got off our flight from Chicago to Seattle and we traveled for business and they told us our connecting flight was over booked and their was no seats asking people to take a delayed next flight and they don’t tell anyone coughing to wear masks seats 30A-B were terrible during the flight no one wants to sit next to people coughing all around I don’t want to be sick traveling for work or get sick anytime it’s very upsetting the staff doesn’t take this stuff serious to tell them to wear masks when they see people coughing and sneezing

Those seats were way too narrow. I had the middle seat, one person was a very skinny person and we still couldn’t avoid touching each other anytime one of us moved. The other person was larger and we were basically sitting in each others lap the entire flight. There was zero entertainment. The flight was long enough to justify tvs, but no. Gotta sit there in your infant seat and twiddle your thumbs.

Fight crew was not very attentive and the bastions were gross!

Our flight was great we left Kona earlier and got into LAX almost an 1hour earlier as well. LAX AA is in repair so to get out and found our bus to get pick up was a bit confusing.

Plane was good but was delayed. probably not AA fault but caused a 1 hour delay. Seating was cramped.

5 hour flight - full flight - not enough room to use my computer - slightly delayed - Admirals club was excellent quality food, drink made up for flight seating. No food offerred on flight, you ahd to prebook.

I had the exit seat with all the leg room I could ask for. Great!

I wish there were no credit card announcements. I paid hundreds of dollars, I don't need to pay again by sitting through advertisements.

We experience delays on departure and connecting flights resulting in 14 hour to our next departure. We were accommodated with a night's stay but was only provided a 12 dollar meals accommodation. The airlines rules state.at least 50 dollars. In any case, it can not make up for the whole day missed on our vacation in Sydney Australia.

I can say I will not be taking this airline again any time soon. Seat were uncomfortable and too tight. Lack of chair screen and little overhead space.

Plane felt so crowded and tightly packed. The chair itself was not comfortable.

The guy with severe body odor sat next to me. For the whole duration of the flight it was a torture. The airline should have better policy on limiting people with bad body odor to board the flight. Passengers should not be the ones to endure bad odor for the whole duration of the flight. The airline should be e the one to ensure decent air quality for ever passenger.

They charged me 212.00 for a heavy check in bag at the gate. The pricing and process was so confusing - as if it was designed to purposefully gouge customers who need to board plane. That experience combined with the outrageous price charged will prevent me from ever flying Spirit again. And I’ll be sure to tell the story to anyone who cares to hear.

The text told me it was changed to Terminal E and Gate D5. But with no one on site to ask questions there was confusion on where to go as all the gates were E's. Then we took the skyline to the D area. We left to get something to eat. No announcement was made but my daughter happened to asked and they told her our gate was moved to D12. I will not fly Spirit again.

The agent at the check in desk was absolutely rude. The rest of the team after that was good, but the check in process at LAS was miserable. The woman at the desk spoke like we were stupid and was rude throughout the process.

Its so random that they only allow 40 pounds on checked bags when all airlines take 55. They then charge you for each 10 extra pounds, so my checked suitcase was $130 and the flight $30 ... its like whattt, im for sure not traveling with Spirit again

Lower price not worth it. Delayed missed connection. Would have taken 24 hours to get to Atlanta. No takes your vouchers making them useless. Never again.

So bad. The check in process was laborious and the check in agent didn't seem to know how to manage the process efficiently and was confused about how to check in my son's sports equipment. The baggage fees were outrageous and so expensive. $90 for a carry on bag? And $200 additional for 2 check ins. The security lines were insanely long and the terminal was not very nice in the Spirit area. $5 for a water on board. It was my first and last time flying Spirit - I tried to save $ by flying them due to the accommodating schedule but I should have paid for Southwest, because it would've actually ended up less expensive due to the free bags with Southwest. There were no charging ports on the airplane, no wifi and really uncomfortable seating. The flight crew were great though, courteous and efficient in their boarding. Flight was delayed 1 hour, but we made up 15 minutes in flight.

My experience was better than expected. What I did find not so great was the seats. Very little room, they did not recline and the tray table was the size of a post card. There was no food to try, just standard snacks that you had to pay for and I don’t know of any entertainment. I would fly again even though everything was an upcharge. Flight was on time with little disturbance

thy don't even ofer water we have to buy it for $4.49 and paid for our cary on bags $100 each we never will fly in this company again.

Super cool and laid back, three lovely ladies. Couldn’t ask for better service.

Six hour delay. Poor customer service. No voucher. Bad communication. Missed important appointments.

Our flight was delayed an hour, then when we got to board our flight finally, we were waiting in our seats for take off for 45 minutes before it was communicated that there was a maintenance issue therefore we waited on the plane for over an hour while that was resolved. We did not get to Phoenix until almost 3 hours after we were originally supposed to. This was the first and last time I will be flying Frontier.

Flight was canceled with little warning. Flight was rebooked through Ontario, California and connecting flight was delayed by over three hours. Frontier is living up to their Greyhound of the skies reputation for sure.

I purchased a carry on bag online…was supposed to cost $72 but after a whole slew of bs charges, the total was over $175.00. Because of these hidden charges, I will not even consider flying Frontier ever again. It’s just not worth the hassle. I’m scratching this company off my list forever.

Flight was OK. Seats were good no cell phone charges on the plane no TVs or entertainment.

They cancelled the flight then did nothing to help us rebook. It was awful - I won’t fly with them again

The truck that was refueling the plane drove away with the hose still connected to the plane and ripped part of the plane off with it

The boarding time. I was in Section 1 the lady in charge just let people in section 3 without see us. Make a line , I have to step out and ask her. We were in the line and she just take my ticket and that’s it, so if I don’t ask her she could leave us at the end! We paid more for that privilege and. She doesn’t care….

See my previous comment which is mostly about our flight from Phoenix to SFO

Terrible. Initially we were shocked by the outrageous baggage fees we needed to pay at check in for our so-called "discounted, economy flight" - we paid over $200 (!!) for one check-in and 2 carry-on bags - this felt like a real bait-and-switch" scam. Our flight from Phoenix to SFO was delayed by 4 hours. Multiple apparent causes (from needing to make space for other planes that were landing late to problem with cabins pressure system, and whatever...). After de-boarding and re-boarding we still waited at least an hour on a cramped, poorly ventilated plane before take-off. Seats were cramped, uncomfortable - did not recline at all. No water until we were flying for a while. No complimentary snacks. Upon arrival at SFO my luggage was sent upstairs to the check-in counter. The customer service person there refused to let me examine a bunch of bags that were sitting on a nearby cart because it was "behind the counter", rather made me wait until another attendant did an exhaustive and failed (?computer) search, came back and told me they were unable to locate my bag. I asked her to look on the cart, lo and behold, there was my bag just a few feet away! Missed my choir rehearsal that evening due to all of the delays. One more thing, a few days later my husband and I tested positive for Covid. Since we both are fully vaccinated, careful about masking and have never had Covid previously, we will never know, but suspect we may have acquired the infection during the prolonged wait on your poorly ventilated plane (person in the row in front of us was coughing). After registering a complaint, we received a measly $50 voucher for future flights. Needless to say we have no intention of flying with Frontier Airlines ever again.

Book cheap flights from Seattle to Ontario

Recent one-way flight deals

 
Only flying one-way? Below are some of the best one-way flight deals from Seattle to Ontario found on KAYAK in the last 72 hours.
6/18Tue
nonstopFrontier
2h 44mSEA-ONT
$49
5/28Tue
nonstopFrontier
2h 44mSEA-ONT
$50
6/5Wed
1 stopDelta
6h 43mSEA-ONT
$88
5/25Sat
nonstopDelta
2h 39mSEA-ONT
$94
5/29Wed
1 stopAmerican Airlines
4h 45mSEA-ONT
$98
7/30Tue
nonstopAlaska Airlines
2h 33mSEA-ONT
$104
5/27Mon
nonstopAlaska Airlines
2h 33mSEA-ONT
$109
5/28Tue
1 stopUnited Airlines
6h 59mSEA-ONT
$123
5/29Wed
1 stopUnited Airlines
6h 59mSEA-ONT
$128
5/16Thu
1 stopAmerican Airlines
4h 45mSEA-ONT
$174

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Search by airline

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Last minute flights from Seattle to Ontario

Last minute flight, train and bus deals

 
These last-minute flight deals are the cheapest flights found on KAYAK in the last 72 hours for flights from Seattle to Ontario that are departing in the next 10 days.
5/8Wed
multi-stopFrontier
12h 05mSEA-ONT
5/14Tue
multi-stopFrontier
12h 07mONT-SEA
$163
5/8Wed
multi-stopFrontier
12h 05mSEA-ONT
6/2Sun
nonstopFrontier
2h 53mONT-SEA
$207
5/8Wed
nonstopAlaska Airlines
2h 33mSEA-ONT
6/2Sun
nonstopAlaska Airlines
2h 45mONT-SEA
$427
5/8Wed
multi-stopUnited Airlines
7h 40mSEA-ONT
5/18Sat
multi-stopUnited Airlines
6h 07mONT-SEA
$444
5/4Sat
nonstopAlaska Airlines
2h 33mSEA-ONT
5/13Mon
nonstopAlaska Airlines
2h 38mONT-SEA
$447
5/8Wed
multi-stopUnited Airlines
6h 28mSEA-ONT
5/15Wed
multi-stopUnited Airlines
6h 07mONT-SEA
$455
5/6Mon
nonstopDelta
2h 40mSEA-ONT
5/11Sat
nonstopDelta
2h 57mONT-SEA
$482
5/7Tue
nonstopDelta
2h 39mSEA-ONT
5/12Sun
nonstopDelta
3h 01mONT-SEA
$492
5/8Wed
multi-stopAmerican Airlines
4h 45mSEA-ONT
5/18Sat
multi-stopAmerican Airlines
11h 20mONT-SEA
$726
5/6Mon
multi-stopAmerican Airlines
6h 47mSEA-ONT
5/13Mon
multi-stopAmerican Airlines
11h 20mONT-SEA
$753

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Seattle - Ontario Flights

Departure:

Seattle (SEA)United States

Destination:

Ontario (ONT)United States

Return flight deals:

Ontario - Seattle

Cabin classes:

$341
$586
$551
$58