Frontier's UpFront Plus seats guarantee an empty middle seat for extra comfort.
Frontier offers Zone 1 boarding with carry-on purchase or special fare bundles.

Most accurate provider | CheapOair 3 stars |
|---|---|
Most trusted provider | CheapOair 3 stars |
Round-trip from | $113 (Kiwi.com) |
One-way from | $61 (Cheapflightsfares) |
Popular in | March |
Cheapest in | October |
Average price | $256 |
Good round-trip deal | $180 or less |
Good one-way deal | $126 or less |
Fly from
Fly to
Route
Depart
Return
Price
ChicagoPhiladelphia
ORD - PHL
ORDPHL
Chicago O'Hare Intl
Wed 12/31
2:15 pm-5:30 pm
Nonstop2h 15m
Philadelphia
Mon 1/5
3:40 pm-10:49 am
1 stop20h 09m
ChicagoPhiladelphia
ORD - PHL
ORDPHL
Chicago O'Hare Intl
Wed 12/31
6:15 pm-9:31 pm
Nonstop2h 16m
Philadelphia
Thu 1/1
6:35 am-8:03 am
Nonstop2h 28m
ChicagoPhiladelphia
ORD - PHL
ORDPHL
Chicago O'Hare Intl
Wed 1/21
11:20 am-2:31 pm
Nonstop2h 11m
Philadelphia
Sat 1/24
6:30 am-7:59 am
Nonstop2h 29m
ChicagoPhiladelphia
ORD - PHL
ORDPHL
Chicago O'Hare Intl
Wed 1/7
4:49 pm-12:51 am
1 stop7h 02m
Philadelphia
Sat 1/10
5:05 am-11:35 am
1 stop7h 30m
ChicagoPhiladelphia
MDW - PHL
MDWPHL
Chicago Midway
Wed 2/18
7:00 am-5:32 pm
1 stop9h 32m
Philadelphia
Wed 2/25
11:40 am-7:07 pm
1 stop8h 27m
ChicagoPhiladelphia
MDW - PHL
MDWPHL
Chicago Midway
Wed 1/21
10:00 am-12:55 pm
Nonstop1h 55m
Philadelphia
Sat 1/24
4:15 pm-5:30 pm
Nonstop2h 15m
ChicagoPhiladelphia
MDW - PHL
MDWPHL
Chicago Midway
Fri 1/23
2:15 pm-5:05 pm
Nonstop1h 50m
Philadelphia
Tue 1/27
5:40 am-7:00 am
Nonstop2h 20m
ChicagoPhiladelphia
MDW - PHL
MDWPHL
Chicago Midway
Wed 1/21
10:00 am-12:55 pm
Nonstop1h 55m
Philadelphia
Sun 1/25
1:40 pm-2:55 pm
Nonstop2h 15m
ChicagoPhiladelphia
ORD - PHL
ORDPHL
Chicago O'Hare Intl
Sun 1/18
11:20 am-2:31 pm
Nonstop2h 11m
Philadelphia
Sun 1/25
1:10 pm-2:40 pm
Nonstop2h 30m
ChicagoPhiladelphia
ORD - PHL
ORDPHL
Chicago O'Hare Intl
Wed 2/18
6:02 pm-8:12 am
2 stops13h 10m
Philadelphia
Wed 2/25
11:40 am-4:52 pm
1 stop6h 12m
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy2 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*1 star | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*2 stars | |
| Price Accuracy2 stars | Trust Score*3 stars |
Booking 85 days in advance of your planned departure date is, on average, the best time to get cheap flights from Chicago to Philadelphia. The general trend is that the closer you book to the departure date, the more expensive your flight will be.
Currently, January is the cheapest month in which you can book a flight from Chicago to Philadelphia (average of $37). Flying from Chicago to Philadelphia in July is currently the most expensive (average of $104). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.
It’s typically best to fly out from Chicago to Philadelphia in the evening. Doing so could potentially save you 27% on the flight price compared to flying in the afternoon, which is usually more expensive.
Travelers seeking maximum savings on their Chicago to Philadelphia flight should consider departing on Monday afternoons when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
The most flights from CHI to PHL are scheduled on a Tuesday (44 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (19 on average).
About 19% of weekly flights between Chicago and Philadelphia have experienced delays in the past year, with the average delay time being 138 minutes.
Historically, flights departing in the morning are less likely to be delayed, whereas flights leaving in the evening tend to experience delays more often.
Tuesday tends to have the lowest number of delays on this route, whereas Thursday has historically faced a higher average of delays compared to other days of the week.
Over the last year, United Airlines have had the lowest number of delays on this route, with just 17% of flights being delayed.
Food
Boarding
Comfort
Entertainment
Crew
Overall
Reviews
Thomas,Dec 2025
SEA - DEN
Food
Boarding
Comfort
Entertainment
Crew
Overall
Reviews
Thomas,Dec 2025
SEA - DEN
Food
Boarding
Comfort
Entertainment
Crew
Overall
Reviews
Thomas,Dec 2025
SEA - DEN
Food
Boarding
Comfort
Entertainment
Crew
Overall
Reviews
Thomas,Dec 2025
SEA - DEN
Food
Boarding
Comfort
Entertainment
Crew
Overall
Reviews
Thomas,Dec 2025
SEA - DEN
Food
Boarding
Comfort
Entertainment
Crew
Overall
Reviews
Thomas,Dec 2025
SEA - DEN
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$63 | Average$260 | FlexibilityNo cancel fee | On-time65% | |
| Cheapest$67 | Average$166 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$108 | Average$477 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$149 | Average$325 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$159 | Average$301 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$177 | Average$308 | FlexibilityNo cancel fee | On-time63% |