Route guide · 812 miles
Cheap Flights from St. Louis to Philadelphia
STL → PHL · Nonstop 2h 9m · Live round-trip fares
If Philadelphia is next on your list, here's the honest picture on fares from St. Louis. The trip covers about 812 miles and takes roughly 2h 9m in the air. Prices on this route reward planners: booking 3–6 weeks ahead is the sweet spot, and the lowest fares tend to sell out fast.
Live fares for STL → PHL are updating. Use the search below for real-time prices.
Search live pricesCheapest recent fare
See live fares
Updated daily
Flight time
2h 9m
Nonstop, typical
Distance
812 mi
STL → PHL
Book ahead
3–6 weeks
Best window, typically
Nonstop airlines
2
American Airlines, Southwest Airlines
Nonstop flights from St. Louis to Philadelphia
The fastest way between the two cities is the nonstop: about 2h 9m for the 812-mile run from STL to PHL. Those flights are flown by American Airlines, Southwest Airlines. Prices behave best when you book 3–6 weeks out.
Booking insights: St. Louis → Philadelphia
- Distance: 812 miles · nonstop flight time: 2h 9m.
- Cheapest upcoming week in the live data starts around Nov 12, with fares from $138.
- Fares tend to bottom out when you book about 3–6 weeks ahead — earlier than that rarely helps, later usually hurts.
- If your dates flex by a day or two, shifting to a midweek departure is the easiest saving there is.
- A free fare alert beats daily checking: we watch this route and ping you when prices drop.
Cheapest month · St. Louis → Philadelphia
November 2026
Every date's recent round-trip fare, at a glance.
Fares from
$138
Cheapest: Sat, Nov 14 — $138
Get this fare →Recent fares found for specific dates in November 2026. Blank days had no recent fare in our data — ask our team and we'll check them for you.
Free fare alerts
Watch St. Louis (STL) → Philadelphia (PHL)
We check this route's fares daily. The moment the price drops, we'll email you — free, unsubscribe anytime.
Talk to a real person
Get St. Louis → Philadelphia flights confirmed by phone
Fares move fast. Call us and we'll confirm the latest price for your dates — or drop your number and we'll call you back. Free, no payment taken on the call.
Request a callback
Flying from St. Louis to Philadelphia: what you need to know
The flight
The nonstop from STL to PHL runs about 2h 9m over 812 miles. It's a comfortable mid-range flight: long enough that seat choice matters a little, short enough that paying up for extras rarely does.
Airlines on this route
American Airlines and Southwest Airlines fly this route nonstop. That matters more than it sounds: the cheapest fare on one carrier is rarely the same product as the cheapest on another. Checked-bag fees, free seat selection and change rules all differ, so compare the full trip cost before you pick a winner. See our airline guides for exactly what each carrier charges — then send an enquiry and we'll confirm the all-in price for your dates.
Leaving from St. Louis (STL)
Plan to be at the airport two hours before a domestic departure — ninety minutes can work at smaller airports outside peak times, but security lines are the one variable you can't control. If you're checking a bag, add time rather than cutting it close. Our St. Louis airport guide covers terminals, parking and ground transport so you can plan the trip to the airport, not just the flight.
Arriving in Philadelphia (PHL)
Before you land, know how you're getting from the airport to where you're staying — it's the part of the trip people forget to plan. The Philadelphia airport guide lays out your ground options, from transit and shuttles to rideshares and rental cars. Flying back the other way? Check Philadelphia to St. Louis fares — prices on the return direction often move on a different rhythm.
When to book
For a trip of 812 miles, booking 3–6 weeks ahead typically lands you in the sweet spot. Leave it to the final two weeks and prices usually climb as the cheapest seats sell out. If your dates are flexible, midweek departures are where the lower fares hide on most domestic routes.
Good to know before you go
- Morning flights are delayed less often than evening ones — earlier departures have the best on-time record.
- Basic economy fares often exclude checked bags and seat selection. Price the whole trip, not the headline fare.
- Get to the airport two hours before departure; security, not the flight, is the part that runs late.
- If you're traveling with only a carry-on, you can skip the bag-drop line entirely with mobile check-in.
- Download the airline's app before you fly; gate changes and delays show up there first.
St. Louis to Philadelphia flight FAQs
How long is the flight from STL to PHL?
A nonstop from STL to PHL clocks in at around 2h 9m for the 812-mile trip. If you're connecting, budget an extra 2–4 hours depending on where you stop.
Are there nonstop flights from St. Louis to Philadelphia?
American Airlines, Southwest Airlines typically operate nonstop flights from STL to PHL. Nonstops are usually cheapest when booked 3–6 weeks ahead of departure.
What is the cheapest month to fly from St. Louis to Philadelphia?
There's no single magic month, but prices on this route generally soften in the shoulder season, when demand dips after the holidays and again in early fall. A free fare alert is the easiest way to catch those windows.
How much are last minute flights from STL to PHL?
Walking up to this route at the last minute is the expensive way to do it — prices inside 7 days of departure climb fast. The 3–6 weeks booking window is where the value sits.
What is a good round-trip deal from St. Louis to Philadelphia?
A good deal is anything at or below the recent fares shown above. Set a free Airfare Deal alert and we'll ping you the moment fares drop.
Which airlines fly from St. Louis to Philadelphia?
You'll mainly see American Airlines, Southwest Airlines on St. Louis to Philadelphia. Checking each against the live fares below is the surest way to find the lowest price for your dates.
How early should I get to St. Louis airport for this flight?
Plan on two hours before departure for a domestic flight — ninety minutes can work at smaller airports outside peak times. If you're checking a bag, earlier is better; the bag-drop line, not the flight, is what runs late.
Do the cheapest fares on this route include a checked bag?
Usually not. Basic economy fares on most airlines include a carry-on but charge extra for checked bags, and seat selection can cost more too. Add up the real total before comparing — a slightly higher regular fare sometimes works out cheaper. Our team confirms the full breakdown with you before you pay.
More cheap flights from St. Louis
How Airfare Deal works — Airfare Deal is a free fare-search and enquiry service. We take no payment online; send an enquiry and our travel team confirms your fare before you pay anything.