$77 Find Cheap Flights from Seattle to Ontario - Compare and Save

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.

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.

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.

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.

Among airlines operating Seattle to Ontario flights:

• Frontier: offers free seat selection
• Alaska Airlines: offers extra legroom; offers free seat selection
• Delta: offers extra legroom; offers free seat selection

Extra legroom and free seat selection availability depends on fare class and route.

3 airlines operate flights between Seattle and Ontario. The airlines offering nonstop flights on this route include:

• Alaska Airlines
• Delta
• Frontier

Flights from Seattle to Ontario usually depart from Seattle/Tacoma Intl (SEA) and arrive at Ontario (ONT).

Here are some options for this route, based on selected ticket types and cabin classes:

• Frontier: a cabin bag and a checked bag in Economy Class
• Alaska Airlines: a cabin bag and a checked bag in Economy Class
• Delta: a cabin bag and a checked bag in First Class

Bag allowance can vary by ticket type, cabin class, route and airline, so travelers should check the fare details before booking.

Four cabin classes are available on flights from Seattle to Ontario:

• Economy Class
• Premium Economy Class
• Business Class
• First Class

Prices vary by airline.

On this route, layover flights are cheaper than nonstop options on average. Layover fares average $191 round-trip via Las Vegas Harry Reid Intl (LAS), compared to $287 for nonstop.

There is no standard. Checked-bag policies vary by airline on this route. Most carriers charge $35–$100 for the first checked bag in economy. Premium fares and elite-status bookings typically include a free checked bag.

The Boeing 737-800 Passenger/BBJ2 (winglets) family is used most often on this route, operated mainly by Alaska Airlines. Other aircraft seen on the route include Airbus A321neo variants.

One-stop flights from Seattle to Ontario most commonly connect through:

• Denver Intl (DEN) - 41% of one-stop connections
• Sacramento Intl (SMF) - 38% of one-stop connections
• Las Vegas Harry Reid Intl (LAS) - 9% of one-stop connections
• Portland (PDX) - 6% of one-stop connections

Denver Intl (DEN) handles the largest share of one-stop connections on this route.

Yes. Being flexible with your travel dates can save you up to 26% on the Seattle to Ontario route. Thursday is the cheapest departure day at $258 round-trip on average, while Sunday is the most expensive at $345, a difference of $87. KAYAK's flexible dates feature shows options up to 3 days before and after your selected dates, making it easier to compare nearby fares.

Morning is the busiest departure period on Seattle to Ontario flights, with 43% of flights leaving in that window. Afternoon departures account for 29%, evening flights for 28%, and night flights for 0%.

Some of the most popular sights in Ontario are Ontario Convention Center, Ontario Mills and Cucamonga-Guasti Regional Park. These are among the most viewed places in Ontario on KAYAK.

These are the earliest and latest flight times available from Seattle to Ontario:

• Earliest: departs at 7:30 am and lands at 10:16 am
• Latest: departs at 9:06 pm and lands at 11:52 pm.

The flight takes about 2h 46m.

Last-minute fares on this route - booked within 2 weeks of departure - run 36% above the route average of $285. Book 11 weeks before departure for the lowest fares.

A nonstop flight from Seattle to Ontario takes 2h 46m, covering 956 miles.

No, a passport is not required for this domestic route, but you will need a real ID-compliant driver's license, a state ID, or another TSA-accepted form of identification.

Yes. Based on fares seen in the past 5 days, round-trip prices on this route showed a wide range, from about $152 to $1,108. That means the highest observed fare was about 7x higher than the lowest one.

One-way fares from Seattle to Ontario are currently lower than usual. Average one-way flight prices are about $121, which is 36% below the typical average for this route.

Flying via Sacramento Intl (SMF) gives the shortest average 1-stop total travel time at 4h 29m, compared with 4h 36m via Portland (PDX) and 4h 56m via San Francisco (SFO).

Ontario Airport (ONT) hosts 5 major car rental companies, with daily rates starting from around $18 for economy cars. Top options include:
· Fox
· Thrifty
· Europcar
· Dollar
· Alamo

Round-trip flights from Seattle to Ontario range from $201 to $380, with an average of $285 over the past 12 months. Anything below $201 counts as a good deal.

Two airlines offer in-flight Wi-Fi on Seattle to Ontario flights:

• • Alaska Airlines
• • Delta