$159 Cheap Frontier Airlines flights Ontario (ONT) to Philadelphia (PHL)

View $159 flight on Wed, Jul 23, 2025Opens in a new window

$159 Cheap Frontier Airlines flights Ontario (ONT) to Philadelphia (PHL)

Prices were available within the past 7 days and start at $159 for one-way flights and $292 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Sat, Aug 9 - Fri, Aug 15
ONT
Ontario
PHL
Philadelphia
$292 Roundtrip, found 2 days ago
$292
Roundtrip
found 2 days ago
Select Frontier Airlines flight, departing Sat, Aug 9 from Ontario to Philadelphia, returning Fri, Aug 15, priced at $292 found 2 days ago
Frontier Airlines
Mon, Aug 18 - Sat, Aug 23
ONT
Ontario
PHL
Philadelphia
$304 Roundtrip, found 8 hours ago
$304
Roundtrip
found 8 hours ago
Select Frontier Airlines flight, departing Mon, Aug 18 from Ontario to Philadelphia, returning Sat, Aug 23, priced at $304 found 8 hours ago
Frontier Airlines
Sat, Aug 2 - Mon, Aug 4
ONT
Ontario
PHL
Philadelphia
$307 Roundtrip, found 5 hours ago
$307
Roundtrip
found 5 hours ago
Select Frontier Airlines flight, departing Sat, Aug 2 from Ontario to Philadelphia, returning Mon, Aug 4, priced at $307 found 5 hours ago
Frontier Airlines
Wed, Aug 13 - Thu, Aug 21
ONT
Ontario
PHL
Philadelphia
$308 Roundtrip, found 11 hours ago
$308
Roundtrip
found 11 hours ago
Select Frontier Airlines flight, departing Wed, Aug 13 from Ontario to Philadelphia, returning Thu, Aug 21, priced at $308 found 11 hours ago
Frontier Airlines
Thu, Aug 21 - Fri, Aug 22
ONT
Ontario
PHL
Philadelphia
$309 Roundtrip, found 1 day ago
$309
Roundtrip
found 1 day ago
Select Frontier Airlines flight, departing Thu, Aug 21 from Ontario to Philadelphia, returning Fri, Aug 22, priced at $309 found 1 day ago
Frontier Airlines
Wed, Aug 6 - Mon, Aug 11
ONT
Ontario
PHL
Philadelphia
$311 Roundtrip, found 12 hours ago
$311
Roundtrip
found 12 hours ago
Select Frontier Airlines flight, departing Wed, Aug 6 from Ontario to Philadelphia, returning Mon, Aug 11, priced at $311 found 12 hours ago
Flights from Ontario (ONT) to Philadelphia (PHL)
Origin airport
Los Angeles - Ontario Intl.
Destination airport
Philadelphia Intl.
Airlines serving
Alaska Airlines, American Airlines, Delta, Frontier Airlines, Hawaiian Airlines, JetBlue Airways, Southwest Airlines, United
Popular airline
American Airlines
Distance
2349 mi

Frequently asked questions

How much is a Frontier Airlines flight from Los Angeles - Ontario Intl. Airport (ONT) to Philadelphia Intl. Airport (PHL)?
Apply the "Price (lowest to highest)" filter on Expedia to search for cheap Frontier Airlines return flights from $292 from ONT to PHL. Affordable one-way fares from $159 are also on offer.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.
What is the cheapest month to fly from ONT to PHL with Frontier Airlines?
Frontier Airlines flights to Philadelphia tend to be cheaper in the off-peak months of January and February. Whether you need a one-way or round-trip ticket, you could land a better deal then.
What is the cheapest time to book flights from Los Angeles - Ontario Intl. Airport (ONT) to Philadelphia Intl. Airport (PHL) with Frontier Airlines?
Search for cheap Frontier Airlines flights from Los Angeles - Ontario Intl. Airport (ONT) to Philadelphia Intl. Airport (PHL) one to three months ahead of your day of departure. Travelers who book domestic flights 34 to 86 days in advance can save 25% compared to those who book just 6 to 12 days ahead. No matter the fare class and itinerary, the best day to book a domestic flight is generally Sunday and the most expensive day tends to be Monday. Passengers who book on a Sunday can save 6% on average compared to those who book their travel on a Monday.**Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC's global airline sales database.
Does Frontier Airlines fly nonstop from Los Angeles - Ontario Intl. Airport (ONT) to Philadelphia Intl. Airport (PHL)?
To figure out if there's a direct journey from ONT to PHL with Frontier Airlines or any other carriers, use our "Nonstop" filter when looking for tickets.
What is the earliest Frontier Airlines flight from ONT to PHL?
Find Frontier Airlines's earliest flights from ONT to PHL by selecting our "Morning" and "Early Morning" filters. Not only will you arrive at your destination sooner, early departures also have a 20% less chance of being canceled.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
What airports does Frontier Airlines fly into in Philadelphia?
Frontier Airlines flights from Los Angeles - Ontario Intl. Airport (ONT) to Philadelphia come in to land at Philadelphia Intl. Airport (PHL). This is the main gateway to this city.
Why fly with Frontier Airlines from ONT to PHL?
Journey from ONT to PHL with Frontier Airlines and enjoy a range of perks starting with a rewarding loyalty program. When you book through Expedia as a Frontier Miles and One Key™ member, you may also earn OneKeyCash™* to use on select future travel purchases.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.
Can I change or cancel my Frontier Airlines flight from Los Angeles - Ontario Intl. Airport (ONT) to Philadelphia Intl. Airport (PHL)?
It's generally possible to cancel or reschedule your flight, although there may be additional fees if you booked more than 24 hours ago. Need flexible options? Make use of Expedia's "No cancel fee" or "Changes included" filter to find flights that won't charge extra if you need to adjust your plans. To make modifications, visit "Trips," select your flight and click on "Manage Booking" for more details.

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*Available to One Key members.