ONT - PHL

$100 Find Cheap Flights from Ontario to Philadelphia

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Ontario to Philadelphia departing on 2/27. 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
1 adult, Economy, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights to Philadelphia

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Ontario to Philadelphia, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Ontario to Philadelphia, as well as popular online travel agencies
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Everything you should know

Cheapest round-trip
$200
Overall average: $306
Frontier
Fri 2/27Sun 3/1
ONT - PHL • 1 stop
Cheapest one-way
$100
Typical prices: $180-$455
Frontier
Fri 2/27
ONT - PHL • 1 stop
Top airlines
Frontier
Cheapest • from $271 (round-trip)
Southwest
Best reviews • 8.0 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
When to book
4 weeks
in advance
Our data shows that travelers who book at least 4 weeks in advance save around 31% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
February
Cheapest • 25% price drop
December
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
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Flight Deals
Booking Insights
Flight Deals

Cheap Flights from Ontario to Philadelphia (ONT-PHL)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Ontario to Philadelphia 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 for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Ontario to Philadelphia

Fri, Feb 27 - Sun, Mar 1
Frontier Logo
6:00 am - 5:55 pm
ONT
-
PHL
8h 55m1 stop
Frontier Logo
5:47 pm - 11:59 pm
PHL
-
ONT
9h 12m1 stop
$200Frontier
Fri, Feb 20 - Sun, Feb 22
Frontier Logo
2:21 pm - 1:12 am
ONT
-
PHL
7h 51m1 stop
Frontier Logo
6:45 am - 2:29 pm
PHL
-
ONT
10h 44m1 stop
$201Frontier
Mon, Jan 19 - Sun, Feb 1
Frontier Logo
8:32 am - 1:21 am
ONT
-
PHL
13h 49m1 stop
Frontier Logo
6:00 am - 4:26 pm
PHL
-
ONT
13h 26m1 stop
$210Frontier
Mon, Jan 19 - Mon, Feb 2
Frontier Logo
8:32 am - 1:21 am
ONT
-
PHL
13h 49m1 stop
Frontier Logo
8:30 am - 2:27 pm
PHL
-
ONT
8h 57m1 stop
$220Frontier
Fri, Apr 10 - Sun, Apr 12
Frontier Logo
6:00 am - 5:31 am
ONT
-
PHL
20h 31m1 stop
Frontier Logo
8:36 pm - 11:59 pm
PHL
-
ONT
30h 23m1 stop
$221Frontier
Thu, Feb 12 - Sun, Feb 15
Frontier Logo
6:05 am - 4:37 pm
ONT
-
PHL
7h 32m1 stop
Frontier Logo
5:42 pm - 11:59 pm
PHL
-
ONT
9h 17m1 stop
$235Frontier
Mon, Feb 16 - Sun, Feb 22
Frontier Logo
2:06 pm - 1:02 am
ONT
-
PHL
7h 56m1 stop
Frontier Logo
6:45 am - 2:29 pm
PHL
-
ONT
10h 44m1 stop
$260Frontier
Sun, Mar 1 - Mon, Mar 16
Frontier Logo
6:10 am - 4:37 pm
ONT
-
PHL
7h 27m1 stop
Frontier Logo
8:20 am - 2:46 pm
PHL
-
ONT
9h 26m1 stop
$261Frontier
Thu, Feb 12 - Sun, Feb 15
Frontier Logo
2:08 pm - 11:29 am
ONT
-
PHL
18h 21m2 stops
Frontier Logo
5:42 pm - 11:59 pm
PHL
-
ONT
9h 17m1 stop
$266Frontier
Thu, Feb 12 - Mon, Feb 16
Frontier Logo
6:05 am - 4:37 pm
ONT
-
PHL
7h 32m1 stop
Frontier Logo
7:12 pm - 11:59 pm
PHL
-
ONT
7h 47m1 stop
$269Frontier
Booking Insights

KAYAK's insights & trends for Ontario to Philadelphia flights

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

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Ontario to Philadelphia, 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 Ontario to Philadelphia is February, where tickets cost $306 (return) on average. On the other hand, the most expensive months are October and December, where the average cost of round-trip tickets is $482 and $476 respectively.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Ontario to Philadelphia, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from Ontario to Philadelphia, you should book around 4 weeks before departure, which saves you about 31% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 17 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$100
Best time to beat the crowds but there is an average 9% increase in price.
Most popular time to fly with an average 16% increase in price.
Flight from Ontario to Philadelphia

When to book flights from Ontario to Philadelphia

Are your dates flexible? Find out the best times to travel from Ontario to Philadelphia 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 Ontario to Philadelphia

  • Which amenities can I enjoy if I upgrade to business class on flights from Ontario to Philadelphia?

    On-board amenities on the Ontario to Philadelphia flight route can vary depending on the airline. Some exclusive amenities when flying business class include additional luggage allowance, in-flight entertainment, complimentary snacks and drinks, a lie-flat seat, a blanket, and additional legroom. So, upgrading to business class is a great decision on this long-haul flight.

  • What are the common layovers on flights from Ontario to Philadelphia?

    After booking cheap flights from Ontario to Philadelphia, expect a stop or more depending on your airline's flight route. The layover city and duration also vary among airlines. The common layovers are major cities, including Phoenix, Chicago, Charlotte, Dallas, Houston, Denver, Las Vegas, Houston, Salt Lake City, Austin, Atlanta, Oakland, Dallas, Austin, San Francisco, Portland, Orlando, and Seattle.

  • What is the carry-on and checked luggage allowance in economy class for flights from Ontario to Philadelphia?

    The carry-on and checked luggage allowances depend on the airline. If you book Frontier Airlines, your carry-on should be 24 x 16 x 10 inches at most. You’re allowed to bring an additional bag weighing at most 50 lb. If you book American Airlines, your carry-on should be a maximum of 22 x 14 x 9 inches, and another bag with a maximum weight of 50 lb is allowed.

  • What’s the most convenient way to travel from Philadelphia International Airport to downtown Philadelphia?

    The airport line train is a reliable way to travel to downtown Philadelphia from PHL airport. These trains depart hourly, and the trip takes about 24 minutes. Another option is the Line 37 bus that gets to the city in approximately 39 minutes. You can also rent a car at the airport terminal and drive to your destination.

  • What is the cheapest flight from Ontario to Philadelphia?

    In the last 3 days, the lowest price for a flight from Ontario to Philadelphia was $100 for a one-way ticket and $200 for a round-trip.

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

    No, a passport isn't needed to fly from Ontario to Philadelphia. However, local authorities might ask for an official ID.

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

    We unfortunately don’t have that data for this specific route.

  • Which airline alliances offer flights from Ontario to Philadelphia?

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

  • What is the most popular layover when flying to Philadelphia from Ontario?

    Phoenix is the most popular layover city among KAYAK users traveling from Ontario to Philadelphia.

  • Which is the best airline for flights from Ontario to Philadelphia, Southwest or Delta?

    The two airlines most popular with KAYAK users for flights from Ontario to Philadelphia are Southwest and Delta. With an average price for the route of $495 and an overall rating of 8.0, Southwest is the most popular choice. Delta is also a great choice for the route, with an average price of $413 and an overall rating of 7.9.

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

    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 Ontario to Philadelphia.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Philadelphia from Ontario 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 Ontario to Philadelphia?

    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 Philadelphia with an airline and back to Ontario with another airline. Booking your flights between Ontario and PHL 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 Ontario to Philadelphia?

    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 Philadelphia from Ontario up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

KAYAK’s top tips for finding a cheap flight from Ontario to Philadelphia

  • Frontier Airlines offers an eco-friendly journey on cheap flights from Ontario (ONT) to Philadelphia (PHL). This airline ensures environmental sustainability by using fuel-efficient aircraft and reducing carbon emissions during operations.
  • Ontario International Airport (ONT) is a hub for West Coast Air. At the same time, Philadelphia International Airport (PHL) is a hub for American Airlines. This airport is a gateway for transatlantic and European destinations.
  • The Line 61 bus offers a convenient journey from downtown Ontario to ONT airport. These buses arrive at the airport in about 10 minutes and depart every 30 minutes. You can also take a shuttle or a taxi to arrive at the airport in approximately 5 minutes.
  • You can book Aer Lingus from Ontario to Philadelphia if you need a special meal. This airline offers a wide range of special meals, including gluten-free, vegetarian, and diabetic. You need to order up to 24 hours before departure, but for kosher meals, you must request 48 hours prior to your flight.
  • PHL airport serves several nearby cities. After arriving, you can visit Darby to the north, Woodbury to the west, Springfield to the northwest, Chester to the southwest, and Camden to the northeast. You can rent a car at the airport and drive to your destination.

Reviews of the top 5 airlines serving from Ontario to Philadelphia

 
See real verified KAYAK customer reviews for airlines flying from Ontario to Philadelphia. 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 Ontario to Philadelphia? 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
SouthwestOverall score based on 4251 reviews
7.5Entertainment
8.0Comfort
7.0Food
8.6Crew
8.1Boarding
Airline reviews

The boarding and seat assignment system no longer works for me, but I know it is being replaced. Otherwise, I am good with the overall experience.

8.0 ExcellentRussell, Dec 2025
SAN - OAK
Read more Southwest reviews

The boarding and seat assignment system no longer works for me, but I know it is being replaced. Otherwise, I am good with the overall experience.

The lead steward kept singing about "San Francisco" and hotel California---more annoying than humorous....needs work. Flight was smooth and on time.

San Diego airport is brand new, spacious, airy and very smooth checkin at SW baggage drop.

Crew could have been friendlier, maybe I'm spoiled by SW crews. In flight wifi was good. Would be nice to have more food offerings on a 4 plus hour flight

Ever since Southwest starting charging for bags, passengers don't want to pay to check their bags, so the gate agents have to beg people to check their roller bags now because there's "not enough space". This was a terrible business move by Southwest.

Sacrament staff are always polite and helpful. Airport is easy to maneuver and boarding is straightforward.

As always, the entire Southwest experience was wonderful, from online booking to flight to baggage retrieval. Very grateful.

The weather could have been better. There was a 40 minute ATC delay in SFO because of marine fog and a micro cell storm delayed landing and take-off at Nashville. The gate was changed 5 minutes from boarding from gate B3 to gate C23 at Nashville airport.

The cabin was quiet for the redeye flight. The area was clean. The staff was great. The 787 Max was in good condition. Drawbacks were that the seat widths were tight for some passengers. The seat padding was at best average and for a long flight uncomfortable.

Delayed flight. Nicest crew member was a SW pilot flying seated next to me who kindly move to seat the final passenger. Flight extra delayed. My cup of refreshment of ginger ale was so packed with ice it was literally 2 sips.

The flight was delayed for about 2 hrs. Other than it, it was good.

I am extremely disappointed that delta internal pilot manuals now refer to the Gulf of Mexico as the “gulf of America”. You can bow down to the Orange turd on your own. I will never fly delta again

I noticed that the planes seem to be outdated. There was no entertainment per se. Also, the waiting area did not have any working electrical outlets

No lunch on a x-country flight scheduled for 10:50 am departure, arrived 5+ hrs later. That requires a black box label before you pay for the tickets. Worst, when I checked in online, it's specifically said that lunch was served on his flight for economy Plus passengers.

Our flight from SFO to MSP was right on time on 11/15/2025. No delays. As we approached MSP at about 8 pm, we circled in the air until 8:40 pm so I don't call that efficient for MSP. I think the captain should announce the delay and why. (as if we all don't know that we are just circling around the area, slowing down, speeding up, slowing down.) Thank you. Marilyn Fischer

Staff were friendly and happy. Delta could make sure passengers that don't have the app know of changes. Without Kayak I would not have known about the change of gate or the delay. Kayak was faster to notify me.

The flight used a B767 with a very old interior from before 2014. The entertainment system did not work at all during the flight despite attempts to reset the system. It was like they flew this route just to be competitive.

Delayed flight (1hour) plus a long layover after an overnight flight with no backup plane available.

Flight delayed for two and half hours and then canceled altogether due to mechanical issues. No mechanic onsite to fix so had to send one from LAX.

Delayed due to thunderstorms and no in-flight service due to rough weather — both of which are out of Delta’s control. Flight was good overall.

I boarded flight UA#1318 at Sacramento International Airport going back to Houston TX. The flight was scheduled at 5:10am. I was able to check in virtually using the United Airlines app. When I entered the airport, there was no one outside assisting with checked bags as it was for Delta Airlines. Immediately upon entering, there was a LONG, EXTREMELY LONG line to the kiosks to get boarding passes. I stand in line to get boarding passes then had to move to ANOTHER EXTREMELY LONG line to get my bags checked in. While standing in this line, we noticed an agent taking customers to 3 at a time to her station to check their bags in. Lucky for me, she called me back, checked my bags for me and I was on my way. I then encountered another long line at the TSA check and to avoid I ending up having to sign up for CLEAR to bypass it. So glad, I did.,...Both of my flights were great with no issues, butthe check in progress at Bush Airport was so much smoother. Check-in at SMF airport needs to be anaylzed and corrected. Do better United, I know you can....thanks

Pushed back only to get deplaned due to a tire damaged by ground crew. They did at least go pretty fast. The bathrooms should be banned under the Geneva convention. No room to even sit straight on the toilet. The under-seat entertainment units block what little leg room there is.

United airlines has the best customer experience from booking to arrival. I always fly United airlines. The mileage program is excellent

Older aircraft, no meal, only food was for purchase. Not impressed United.

Not pleasant trip cross country when the entertainment and WiFi system not working. No entertainment for entirety of route. Staff was rather nonchalant in that they dismissed the problem due to age of plane. It would have been nice to know this up front so I could have come prepared to read or download movies before boarding Coincidentally or not, there was a similar issue with the entertainment system on my previous flight I took on my fist leg of the trip. There are no seat TVs, so you must rely on the app when it works. United can do better. Also, what use it it to pay for boarding group 2 when half of the passengers are in the same line as you?

Premium Plus is a really good idea for longer flights

The flight attendants were great, I joked with one I can’t remember her name, a blond, really sweet. I thought it was run well very professional. This was great i survived Spirit, I know for which I speak.

I was in first class. The outlets at my seat did not work. The plane was shabby and run down. I had prepurchsed a day subscription for internet that was not redeemable. I had to repurchase the internet for my flight and then it didn’t work anyway. Quite disappointed in what was supposed to be the launch of a great vacation.

I understand stuff happens, but plane failures are likely due to lack of maintenance. Additionally, air conditioning wasn't working, no snack/drink service, no WiFi. Fortunately, the crew was communicative and light-hearted. United grabbed another plane and we were able to get to our destination.

Stuck on tarmac for two hours plus a 5.5 hour flight. Rude flight attendant. And no meals, not even for purchase!

the trip to madrid was uncomfortable with my legs touching the seat in front of me

Very crowded flight but what can you expect these days?? Crew was accommodating.

The seats in economy were appeared to be quite thin and lack sufficient cushioning to be comfortable. Perhaps it was my seating position but the plane seemed notably load.

Internet was a bit expensive and did not work ask that week otherwise a good flight

The flight had a delay that made me being in a real rush to take the second flight. The delay was almost for 2 hours. They moved us from gate to gate in 4 times. Once I arrived to Philadelphia, I got to run thorough all the airport, as the train was already closed by that time. So I got sick with asthma for all the running I had to do. And I was the last one to board, when it was almost closed. So irresponsable with the people

The plane was probably full boarding was easy. We were able to check our carry-on luggage for free. It was a return flight through Philly to LA. Never saw a stewardess do a demonstration of emergency Procedures. I think my flight was pretty full

Overall, a good experience. The food, however, was subpar. The breakfast was a joke.

I was late from Jacksonville, FL but the limited interaction I had with the Philly crew was great.

The delays and cancellations kept me stuck in Miami for an additional 24 hours, and the whole thing seemed extremely disorganized

Everything was great except British airways lost our luggage that was gate checked all the way through to Italy. No one knows currently where one is and the other one may be in route to Amsterdam to meet us but not sure. If you can Hale’s it would be awesome. The website is not helpful.

Not clean and was told I would get a great seat and it was not great at all

Good- no snacks on a 4+ hour flight is painful but more painful was the lack of WiFi.

When I wanted to check in 3 hours prior to boarding time, the employees mentioned “a little over an hour delay” so I waited for an hour then I went to go look for food in the terminal and most people from that flight were in the same area looking for food. Finally I decided after food to check to see if it’s anytime closer and now it’s 2 mins until boarding closes?! What are you kidding me? I didn’t receive anything via sms about boarding now nor via email or on the intercom. I luckily made it through, barely, and then there’s no room for my carry on mind you I’m in the very first row so I had to place my purse in one further row back and my carry on sections down. Not sure who pays for better seats to get your stuff placed all over the plane but that was the worst experience I’ve ever had flying with anyone.

This airline sucks. They offer low rates then charge you for everything, the app does not work well, the seats are the most uncomfortable. Maintenance issues on the flight, and you still have to sit through their credit card commercials. People are nice enough but does not make up for overall poor experience.

Cancelled flight after I arrived at airport after 75 min drive and parking. Next flight was 4 days in the future. Had to scramble and buy a much more expensive flight on another carrier.

I liked the turn-style feature at gate 209B at LAX. Very efficient process. The gate staff also made several, clearly directed announcements so I felt very informed.

The seats were awful, hard plastic covered in sheet vinyl. The airline tries to scam you into paying extra to get seat together when the flight wasn’t full. They were going to separate a family with young children but my wife who had a row to herself gave up her seat so the young mom could be with her young boys. I’m never giving this airline my money again.

It was a short flight so no food or entertainment….

Frontier had yet another flight cancellation. Have never made a complete round trip with this airline without at least one leg getting cancelled. Miserable flights - dirty, uncomfortable planes that apparently always have issues since I've had multiple delays and cancellations with them.

Flight was delayed 3 times, would have been nice to have received text message instead of email notifications. Frontier app wasn’t even updated accordingly, no gate number disclosed. No agent at front desk of gate to inform of delay. Very confused and left if the dark

Everything you need to know for your flight from Ontario to Philadelphia

Information on your arrival and departure airports