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Cheap flights from Knoxville to St. Louis from $139

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 4/13. 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

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Cheap round-trip flights

Enter your travel dates to find the best prices.
American Airlines Logo
6:00 am - 9:37 am
TYS
-
STL
4h 37m
1 stop
American Airlines Logo
6:55 pm - 11:59 pm
STL
-
TYS
4h 04m
1 stop
$233American Airlines
Wed, Apr 8 - Wed, Apr 8
Southwest Logo
7:05 am - 1:00 pm
TYS
-
STL
6h 55m
2 stops
Southwest Logo
2:30 pm - 7:40 pm
STL
-
TYS
4h 10m
1 stop
$238Southwest
Wed, Apr 8 - Wed, Apr 8
Southwest Logo
7:25 pm - 12:05 am
TYS
-
STL
5h 40m
1 stop
Southwest Logo
8:25 am - 2:20 pm
STL
-
TYS
4h 55m
1 stop
$245Southwest
Mon, Apr 6 - Tue, Apr 7
Southwest Logo
6:40 am - 1:35 pm
TYS
-
STL
7h 55m
1 stop
Southwest Logo
5:45 am - 2:20 pm
STL
-
TYS
7h 35m
1 stop
$250Southwest
Sat, May 16 - Tue, May 19
Southwest Logo
6:30 am - 12:30 pm
TYS
-
STL
7h 00m
2 stops
Southwest Logo
10:25 am - 8:50 pm
STL
-
TYS
9h 25m
2 stops
$255Southwest
Mon, Apr 6 - Tue, Apr 7
American Airlines Logo
6:54 pm - 10:59 pm
TYS
-
STL
5h 05m
1 stop
American Airlines Logo
5:20 am - 12:30 pm
STL
-
TYS
6h 10m
1 stop
$257American Airlines
Thu, May 7 - Mon, May 11
Southwest Logo
6:45 pm - 11:15 pm
TYS
-
STL
5h 30m
1 stop
Southwest Logo
10:35 am - 6:30 pm
STL
-
TYS
6h 55m
2 stops
$262Southwest
Thu, May 14 - Sat, May 16
American Airlines Logo
7:53 am - 11:47 am
TYS
-
STL
4h 54m
1 stop
American Airlines Logo
3:24 pm - 10:56 pm
STL
-
TYS
6h 32m
1 stop
$265American Airlines
Thu, May 7 - Tue, May 12
American Airlines Logo
6:54 pm - 10:59 pm
TYS
-
STL
5h 05m
1 stop
American Airlines Logo
5:20 am - 12:30 pm
STL
-
TYS
6h 10m
1 stop
$268American Airlines
Thu, Apr 30 - Sun, May 3
Southwest Logo
6:35 am - 2:55 pm
TYS
-
STL
9h 20m
2 stops
Southwest Logo
10:35 am - 6:30 pm
STL
-
TYS
6h 55m
2 stops
$273Southwest
Thu, May 14 - Sat, May 16

American Airlines flights from Knoxville to St. Louis

Our best American Airlines deals on Knoxville to St. Louis flight tickets
American Airlines
May 7
TYS6:54 pmKnoxville McGhee Tyson
5h 05m
1 stop
STL10:59 pmLambert-St Louis
May 11
STL5:20 amLambert-St Louis
6h 10m
1 stop
TYS12:30 pmKnoxville McGhee Tyson
$257
American Airlines
May 7
TYS7:53 amKnoxville McGhee Tyson
4h 54m
1 stop
STL11:47 amLambert-St Louis
May 12
STL3:24 pmLambert-St Louis
6h 32m
1 stop
TYS10:56 pmKnoxville McGhee Tyson
$265
American Airlines
Apr 30
TYS6:54 pmKnoxville McGhee Tyson
5h 05m
1 stop
STL10:59 pmLambert-St Louis
May 3
STL5:20 amLambert-St Louis
6h 10m
1 stop
TYS12:30 pmKnoxville McGhee Tyson
$268

Southwest flights from Knoxville to St. Louis

Our best Southwest deals on Knoxville to St. Louis flight tickets
Southwest
Apr 7
TYS2:55 pmKnoxville McGhee Tyson
7h 20m
1 stop
STL9:15 pmLambert-St Louis
Apr 14
STL5:45 amLambert-St Louis
7h 35m
1 stop
TYS2:20 pmKnoxville McGhee Tyson
$233
Southwest
Apr 7
TYS12:50 pmKnoxville McGhee Tyson
7h 25m
2 stops
STL7:15 pmLambert-St Louis
Apr 14
STL10:15 amLambert-St Louis
5h 55m
1 stop
TYS5:10 pmKnoxville McGhee Tyson
$238
Southwest
Apr 7
TYS7:05 amKnoxville McGhee Tyson
8h 45m
2 stops
STL2:50 pmLambert-St Louis
Apr 14
STL10:25 amLambert-St Louis
9h 25m
2 stops
TYS8:50 pmKnoxville McGhee Tyson
$243

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 March 15, 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
Quickest round-trip

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Wed 4/8

6:00 am-9:37 am

1 stop4h 37m

Lambert-St Louis

Wed 4/8

6:55 pm-11:59 pm

1 stop4h 04m

$233

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Wed 4/8

7:05 am-1:00 pm

2 stops6h 55m

Lambert-St Louis

Wed 4/8

2:30 pm-7:40 pm

1 stop4h 10m

$238

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Mon 4/6

7:25 pm-12:05 am

1 stop5h 40m

Lambert-St Louis

Tue 4/7

8:25 am-2:20 pm

1 stop4h 55m

$245

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Sat 5/16

6:40 am-1:35 pm

1 stop7h 55m

Lambert-St Louis

Tue 5/19

5:45 am-2:20 pm

1 stop7h 35m

$250

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Mon 4/6

6:30 am-12:30 pm

2 stops7h 00m

Lambert-St Louis

Tue 4/7

10:25 am-8:50 pm

2 stops9h 25m

$255

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Thu 5/7

6:54 pm-10:59 pm

1 stop5h 05m

Lambert-St Louis

Mon 5/11

5:20 am-12:30 pm

1 stop6h 10m

$257

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Thu 5/14

6:45 pm-11:15 pm

1 stop5h 30m

Lambert-St Louis

Sat 5/16

10:35 am-6:30 pm

2 stops6h 55m

$262

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Thu 5/7

7:53 am-11:47 am

1 stop4h 54m

Lambert-St Louis

Tue 5/12

3:24 pm-10:56 pm

1 stop6h 32m

$265

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Thu 4/30

6:54 pm-10:59 pm

1 stop5h 05m

Lambert-St Louis

Sun 5/3

5:20 am-12:30 pm

1 stop6h 10m

$268

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Thu 5/14

6:35 am-2:55 pm

2 stops9h 20m

Lambert-St Louis

Sat 5/16

10:35 am-6:30 pm

2 stops6h 55m

$273

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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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 cheapest month to fly to St. Louis?

In general, July 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 $288. The month of April is another great option to travel to St. Louis, with average flight prices from Knoxville averaging around $293.

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

As of March 2026, prices for Knoxville to St. Louis flights are approximately 25% 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

3h 37m

Direct flights

None
The fastest flight from Knoxville to St. Louis takes 3h 37m
There are no direct flights from Knoxville to St. Louis. There are no popular flight routes from Knoxville to St. Louis.
Search flight deals

  • 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 3h 37m.

  • 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 $198Free CancellationRating
7.1
11,467 reviews
Search American Airlines flights
DeltaPriceFrom $228Free CancellationRating
7.9
8,296 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
Hermann
Fairview Heights
Florissant
Maryland Heights
O'Fallon
Collinsville
St. Peters
Fenton
Alton
Wentzville
Farmington
Edwardsville
Festus
Clayton
Eureka
Litchfield
Glencoe
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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