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Cheap flights from Knoxville to St. Louis from $123

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Knoxville to St. Louis departing on 10/15. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
1 adult, Economy, 0 bags

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from Knoxville to St. Louis

Cheap round-trip flights

Enter your travel dates to find the best prices.
Southwest Logo
5:40 pm - 11:55 pm
TYS
-
STL
7h 15m
1 stop
Southwest Logo
8:25 am - 6:20 pm
STL
-
TYS
8h 55m
1 stop
$237Southwest
Tue, Jul 14 - Wed, Jul 15
Southwest Logo
7:10 am - 1:05 pm
TYS
-
STL
6h 55m
2 stops
Southwest Logo
10:20 am - 5:00 pm
STL
-
TYS
5h 40m
1 stop
$242Southwest
Tue, Jul 14 - Wed, Jul 15
Southwest Logo
7:10 am - 3:20 pm
TYS
-
STL
9h 10m
2 stops
Southwest Logo
10:15 am - 8:25 pm
STL
-
TYS
9h 10m
2 stops
$247Southwest
Tue, Jul 14 - Wed, Jul 15
American Airlines Logo
5:31 pm - 12:04 am
TYS
-
STL
7h 33m
1 stop
American Airlines Logo
5:10 am - 12:34 pm
STL
-
TYS
6h 24m
1 stop
$268American Airlines
Fri, Jul 17 - Tue, Jul 21
Southwest Logo
7:00 pm - 11:55 pm
TYS
-
STL
5h 55m
1 stop
Southwest Logo
10:20 am - 8:25 pm
STL
-
TYS
9h 05m
2 stops
$273Southwest
Sun, Jul 26 - Tue, Jul 28
Southwest Logo
6:40 am - 1:35 pm
TYS
-
STL
7h 55m
2 stops
Southwest Logo
10:45 am - 7:50 pm
STL
-
TYS
8h 05m
2 stops
$278Southwest
Mon, Jul 27 - Tue, Aug 4
American Airlines Logo
6:05 pm - 10:40 pm
TYS
-
STL
5h 35m
1 stop
American Airlines Logo
3:25 pm - 8:59 pm
STL
-
TYS
4h 34m
1 stop
$279American Airlines
Fri, Aug 14 - Mon, Aug 17
Southwest Logo
5:40 pm - 11:55 pm
TYS
-
STL
7h 15m
1 stop
Southwest Logo
8:05 am - 12:05 pm
STL
-
TYS
3h 00m
1 stop
$284Southwest
Tue, Jul 7 - Sun, Jul 12
Southwest Logo
2:45 pm - 6:25 pm
TYS
-
STL
4h 40m
1 stop
Southwest Logo
5:50 am - 12:05 pm
STL
-
TYS
5h 15m
2 stops
$289Southwest
Tue, Jul 7 - Sun, Jul 12
Southwest Logo
7:45 pm - 10:50 pm
TYS
-
STL
4h 05m
1 stop
Southwest Logo
2:30 pm - 9:15 pm
STL
-
TYS
5h 45m
1 stop
$299Southwest
Thu, Jul 16 - Thu, Jul 23

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Southwest flights from Knoxville to St. Louis

Our best Southwest deals on Knoxville to St. Louis flight tickets
Southwest
Jul 14
TYS5:40 pmKnoxville McGhee Tyson
7h 15m
1 stop
STL11:55 pmLambert-St Louis
Jul 15
STL8:25 amLambert-St Louis
8h 55m
1 stop
TYS6:20 pmKnoxville McGhee Tyson
$237
Southwest
Jul 14
TYS7:10 amKnoxville McGhee Tyson
6h 55m
2 stops
STL1:05 pmLambert-St Louis
Jul 15
STL10:20 amLambert-St Louis
5h 40m
1 stop
TYS5:00 pmKnoxville McGhee Tyson
$242
Southwest
Jul 14
TYS7:10 amKnoxville McGhee Tyson
9h 10m
2 stops
STL3:20 pmLambert-St Louis
Jul 15
STL10:15 amLambert-St Louis
9h 10m
2 stops
TYS8:25 pmKnoxville McGhee Tyson
$247

American Airlines flights from Knoxville to St. Louis

Our best American Airlines deals on Knoxville to St. Louis flight tickets
American Airlines
Jul 17
TYS5:31 pmKnoxville McGhee Tyson
7h 33m
1 stop
STL12:04 amLambert-St Louis
Jul 21
STL5:10 amLambert-St Louis
6h 24m
1 stop
TYS12:34 pmKnoxville McGhee Tyson
$268
American Airlines
Aug 14
TYS6:05 pmKnoxville McGhee Tyson
5h 35m
1 stop
STL10:40 pmLambert-St Louis
Aug 17
STL3:25 pmLambert-St Louis
4h 34m
1 stop
TYS8:59 pmKnoxville McGhee Tyson
$279
American Airlines
Jun 28
TYS5:00 amKnoxville McGhee Tyson
4h 32m
1 stop
STL8:32 amLambert-St Louis
Jul 5
STL5:32 amLambert-St Louis
6h 24m
1 stop
TYS12:56 pmKnoxville McGhee Tyson
$407

momondo Fare Finder

 
Customize your flight search to find flights from Knoxville to St. Louis that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 832,500 searches. Data last updated June 16, 2026.
Use the filters below to find and compare flights from Knoxville to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Tue 7/14

5:40 pm-11:55 pm

1 stop7h 15m

Lambert-St Louis

Wed 7/15

8:25 am-6:20 pm

1 stop8h 55m

$237

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Tue 7/14

7:10 am-1:05 pm

2 stops6h 55m

Lambert-St Louis

Wed 7/15

10:20 am-5:00 pm

1 stop5h 40m

$242

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Tue 7/14

7:10 am-3:20 pm

2 stops9h 10m

Lambert-St Louis

Wed 7/15

10:15 am-8:25 pm

2 stops9h 10m

$247

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Fri 7/17

5:31 pm-12:04 am

1 stop7h 33m

Lambert-St Louis

Tue 7/21

5:10 am-12:34 pm

1 stop6h 24m

$268

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Sun 7/26

7:00 pm-11:55 pm

1 stop5h 55m

Lambert-St Louis

Tue 7/28

10:20 am-8:25 pm

2 stops9h 05m

$273

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Mon 7/27

6:40 am-1:35 pm

2 stops7h 55m

Lambert-St Louis

Tue 8/4

10:45 am-7:50 pm

2 stops8h 05m

$278

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Fri 8/14

6:05 pm-10:40 pm

1 stop5h 35m

Lambert-St Louis

Mon 8/17

3:25 pm-8:59 pm

1 stop4h 34m

$279

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Tue 7/7

5:40 pm-11:55 pm

1 stop7h 15m

Lambert-St Louis

Sun 7/12

8:05 am-12:05 pm

1 stop3h 00m

$284

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Tue 7/7

2:45 pm-6:25 pm

1 stop4h 40m

Lambert-St Louis

Sun 7/12

5:50 am-12:05 pm

2 stops5h 15m

$289
Quickest round-trip

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Thu 7/16

7:45 pm-10:50 pm

1 stop4h 05m

Lambert-St Louis

Thu 7/23

2:30 pm-9:15 pm

1 stop5h 45m

$299

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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2

See travel insights to St. Louis from

How to get the cheapest flight ticket from Knoxville to St. Louis

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the typical price of a round-trip flight between Knoxville and St. Louis?

What is the cheapest month to fly to St. Louis?

In general, January is the cheapest month to fly from Knoxville to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $294. The month of September is another great option to travel to St. Louis, with average flight prices from Knoxville averaging around $298.

How have Knoxville to St. Louis flight prices changed over time?

As of June 2026, prices for Knoxville to St. Louis flights are approximately 197% more expensive when compared to flights at the same time last year.

When to book flights from Knoxville to St. Louis

Are you open to changing your travel dates? Check out the ideal times to fly from Knoxville to St. Louis according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Knoxville to St. Louis (TYS to STL) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Knoxville to St. Louis

Fastest flight time

4h 40m

Direct flights

None
The fastest flight from Knoxville to St. Louis takes 4h 40m
There are no direct flights from Knoxville to St. Louis. There are no popular flight routes from Knoxville to St. Louis.
Search flight deals

Frequently asked questions about flying from Knoxville to St. Louis

  • How far is Knoxville McGhee Tyson to Lambert-St Louis by plane?

    Lambert-St Louis is 390.7 mi away from Knoxville McGhee Tyson. By plane, this route typically takes 4h 40m.

  • When did momondo last update prices for flights from Knoxville McGhee Tyson Airport to Lambert-St Louis Airport?

    Prices for flights from Knoxville McGhee Tyson Airport to Lambert-St Louis Airport are updated daily.

  • How many operators does momondo search for flights from Knoxville McGhee Tyson Airport to Lambert-St Louis Airport?

  • How old do you have to be to fly from Knoxville McGhee Tyson Airport to Lambert-St Louis Airport?

    Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Knoxville McGhee Tyson Airport to Lambert-St Louis Airport.

  • What documentation or ID do you need to fly to Lambert-St Louis Airport?

    The required travel and health documents for your Lambert-St Louis Airport trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Lambert-St Louis Airport. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

  • What is the most popular airline from Knoxville to St. Louis?

Best airlines flying from Knoxville to St. Louis

Compare and see reviews for airlines that fly from Knoxville to St. Louis with momondo
Airline
Rating
Free Cancellation
Price
American AirlinesPriceFrom $228Free CancellationRating
7.1
11,667 reviews
Search American Airlines flights
SouthwestPriceFrom $236Free CancellationRating
7.9
4,237 reviews
Search Southwest flights
DeltaPriceFrom $248Free CancellationRating
7.9
8,403 reviews
Search Delta flights

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
St. Charles
Chesterfield
Fairview Heights
Hermann
Maryland Heights
Florissant
O'Fallon
St. Peters
Collinsville
Alton
Wentzville
Clayton
Fenton
Farmington
Festus
Eureka
Litchfield
Edwardsville
Grafton
Shrewsbury

Why use momondo?

Why should I use momondo to find a flight deal from Knoxville to St. Louis?

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from Knoxville to St. Louis. Millions of users trust and use momondo every year so you are in good hands.

Can I find flights from Knoxville to St. Louis with flexible booking policies on momondo?

Yes. All flights to St. Louis from Knoxville on momondo can be compared and filtered by various policies on offer, including flexible booking.

How can momondo help me find flights from Knoxville to St. Louis?

momondo provides multiple filters to help you find the best flight to St. Louis from Knoxville. Filter by price, airline, airports, cabin, aircraft, payment method, number of stops and more.

I’m not ready to book a flight from Knoxville to St. Louis right now. Can momondo alert me if prices change?

If you are not ready to book a flight from Knoxville to St. Louis now, use our insights above to find helpful tips or alternatively set up a price alert, where momondo will track prices on flights to St. Louis and let you know when they change.

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