$126 Cheap Flights from Knoxville (TYS) to St. Louis (STL)

View $126 flight on Tue, Dec 2, 2025Opens in a new window

Popular airlines from McGhee Tyson Airport (TYS) to St. Louis Lambert Intl. Airport (STL)

Cheap Flights from Knoxville to St. Louis (TYS-STL)

Prices were available within the past 7 days and start at $126 for one-way flights and $140 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Thu, Dec 11 - Sat, Dec 13
TYS
Knoxville
STL
St. Louis
$140 Roundtrip, found 1 day ago
$140
Roundtrip
found 1 day ago
Select Frontier Airlines flight, departing Thu, Dec 11 from Knoxville to St. Louis, returning Sat, Dec 13, priced at $140 found 1 day ago
Frontier Airlines
Thu, Nov 6 - Sat, Nov 15
TYS
Knoxville
STL
St. Louis
$153 Roundtrip, found 4 days ago
$153
Roundtrip
found 4 days ago
Select Frontier Airlines flight, departing Thu, Nov 6 from Knoxville to St. Louis, returning Sat, Nov 15, priced at $153 found 4 days ago
Frontier Airlines
Thu, Dec 11 - Wed, Dec 17
TYS
Knoxville
STL
St. Louis
$160 Roundtrip, found 1 day ago
$160
Roundtrip
found 1 day ago
Select Frontier Airlines flight, departing Thu, Dec 11 from Knoxville to St. Louis, returning Wed, Dec 17, priced at $160 found 1 day ago
Frontier Airlines
Thu, Dec 11 - Wed, Dec 17
TYS
Knoxville
STL
St. Louis
$180 Roundtrip, found 5 days ago
$180
Roundtrip
found 5 days ago
Select Frontier Airlines flight, departing Thu, Dec 11 from Knoxville to St. Louis, returning Wed, Dec 17, priced at $180 found 5 days ago
Frontier Airlines
Sun, Dec 14 - Wed, Dec 17
TYS
Knoxville
STL
St. Louis
$193 Roundtrip, found 5 days ago
$193
Roundtrip
found 5 days ago
Select Frontier Airlines flight, departing Sun, Dec 14 from Knoxville to St. Louis, returning Wed, Dec 17, priced at $193 found 5 days ago
Frontier Airlines
Sat, Nov 22 - Sat, Dec 13
TYS
Knoxville
STL
St. Louis
$200 Roundtrip, found 5 days ago
$200
Roundtrip
found 5 days ago
Select Frontier Airlines flight, departing Sat, Nov 22 from Knoxville to St. Louis, returning Sat, Dec 13, priced at $200 found 5 days ago
Southwest Airlines
Tue, May 12 - Tue, May 19
TYS
Knoxville
STL
St. Louis
$249 Roundtrip, found 5 days ago
$249
Roundtrip
found 5 days ago
Select Southwest Airlines flight, departing Tue, May 12 from Knoxville to St. Louis, returning Tue, May 19, priced at $249 found 5 days ago
Delta
Tue, Dec 2 - Wed, Dec 3
TYS
Knoxville
STL
St. Louis
$251 Roundtrip, just found
$251
Roundtrip
just found
Select Delta flight, departing Tue, Dec 2 from Knoxville to St. Louis, returning Wed, Dec 3, priced at $251 just found
United
Sat, Dec 13 - Tue, Dec 16
TYS
Knoxville
STL
St. Louis
$251 Roundtrip, found 4 days ago
$251
Roundtrip
found 4 days ago
Select United flight, departing Sat, Dec 13 from Knoxville to St. Louis, returning Tue, Dec 16, priced at $251 found 4 days ago
American Airlines
Tue, Dec 2 - Sun, Dec 7
TYS
Knoxville
STL
St. Louis
$265 Roundtrip, just found
$265
Roundtrip
just found
Select American Airlines flight, departing Tue, Dec 2 from Knoxville to St. Louis, returning Sun, Dec 7, priced at $265 just found

Find the cheapest month to fly from Knoxville (TYS) to St. Louis (STL)

May is typically the cheapest month to fly

From $198 - $478 per traveler.

Alternative airports near St. Louis

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Lambert-St. Louis Intl. STL. Cheapest option available. Average driving time to city center is 20 minutes. Flights from $329
STL
Lambert-St. Louis Intl.
Cheapest
Average driving time to city center20 min
Flights from $329

Frequently asked questions

How much does a flight from McGhee Tyson Airport (TYS) to Lambert-St. Louis Intl. Airport (STL) cost?
Secure a cheap one-way flight from $126 or cheap return flight from $140 from McGhee Tyson Airport (TYS) to Lambert-St. Louis Intl. Airport (STL) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to see our cheapest flight deals on this route.
What is the cheapest month to fly from McGhee Tyson Airport (TYS) to Lambert-St. Louis Intl. Airport (STL)?
Planning your trip for December is a good way to save, as it's the cheapest month for flights between TYS and STL. You'll often find the lowest fares during the off-season.
What is the cheapest airline that flies from McGhee Tyson Airport (TYS) to Lambert-St. Louis Intl. Airport (STL)?
To find the cheapest airline flying from TYS to STL, use Expedia's filter tool. Customize your search based on your travel needs, such as preferred carriers and flight duration. You can then sort your results by "Price (lowest to highest)" to see the cheapest fares upfront.
How many flights per day from McGhee Tyson Airport (TYS) to Lambert-St. Louis Intl. Airport (STL)?
You'll need to catch a flight with a layover when traveling from McGhee Tyson Airport (TYS) to Lambert-St. Louis Intl. Airport (STL). There are no daily direct flights on this route. However, simply filter your search to include one or two stops to discover the best option for your trip.
What day of the week has the most flights from TYS to STL?
You'll typically find Tuesday the quietest day for flights, while Fridays tend to be the busiest.* However this can vary from season to season and during peak travel times or public holidays.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from McGhee Tyson Airport (TYS) to Lambert-St. Louis Intl. Airport (STL)?
Choose a flight from McGhee Tyson Airport (TYS) to Lambert-St. Louis Intl. Airport (STL) that takes off before 3 PM to reduce the likelihood of delays and cancellations. Departures later than this have a 22% higher chance of being canceled, on average.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
Is it cheaper to buy a plane ticket from McGhee Tyson Airport (TYS) to Lambert-St. Louis Intl. Airport (STL) last-minute?
Last-minute fares from TYS to STL are usually more expensive. For the best rates, start looking for flights early. That being said, if your travel plans are flexible, it's possible to land a cheap fare just before your departure.
Is it cheaper to book a TYS to STL flight and hotel package?
Compared with arranging hotels and flights separately, booking a TYS to STL flight and hotel package with Expedia could result in significant savings. Better yet, having everything in one easy place takes the hassle out of planning your trip. Just secure your flights and choose from our wide range of stays, then customize your trip with other add-ons like tours, activities and car rentals.
Can I cancel or change the date of my flight from McGhee Tyson Airport (TYS) to Lambert-St. Louis Intl. Airport (STL)?
If you reserved your TYS to STL flight within the last 24 hours, you may be able to modify or cancel it at no cost. Depending on the airline and the type of ticket you purchased, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, go to our Customer Service portal for more details.

Travel information

Origin airport
McGhee Tyson
Destination airport
Lambert-St. Louis Intl.
Airlines serving
American Airlines, Delta, Frontier Airlines, Southwest Airlines, United
Roundtrip price
$140
Distance
404 mi

Book with confidence

Knoxville to St. Louis Flights

The cheapest times to fly from Knoxville to St. Louis

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Knoxville to St. Louis are during the month of December. You can find some of the cheapest flights from Knoxville to St. Louis with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Knoxville to St. Louis

Sunday is one of the best days to book for cheap flights from Knoxville to St. Louis: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Knoxville to St. Louis

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Knoxville to St. Louis in 2025. You can also book with separate airlines for your outbound and return journeys, from $126 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Knoxville to St. Louis flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Knoxville to St. Louis airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Knoxville to St. Louis Flights

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*Available to One Key members.