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Cheap flights from Knoxville to St. Louis from $117

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 9/4. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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0 bags

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Find the cheapest flights from Knoxville to St. Louis

Cheap round-trip flights

Frontier Logo
8:40 pm - 9:06 amTYS-STL
13h 26m1 stop
Frontier Logo
7:55 pm - 7:45 pmSTL-TYS
22h 50m1 stop
$225Frontier
Find Deal
Thu, Sep 25 - Sun, Sep 28
Delta Logo
10:24 am - 4:05 pmTYS-STL
6h 41m1 stop
Delta Logo
6:01 am - 10:56 amSTL-TYS
3h 55m1 stop
$229Delta
Find Deal
Thu, Sep 18 - Sun, Sep 21
American Airlines Logo
10:10 am - 1:51 pmTYS-STL
4h 41m1 stop
American Airlines Logo
5:15 am - 11:30 amSTL-TYS
5h 15m1 stop
$239American Airlines
Find Deal
Wed, Aug 13 - Sat, Aug 16
American Airlines Logo
5:20 pm - 9:10 pmTYS-STL
4h 50m1 stop
American Airlines Logo
7:23 am - 2:43 pmSTL-TYS
6h 20m1 stop
$249American Airlines
Find Deal
Fri, Sep 19 - Sun, Sep 21
Delta Logo
5:30 am - 8:09 amTYS-STL
3h 39m1 stop
Delta Logo
6:00 am - 11:05 amSTL-TYS
4h 05m1 stop
$254Delta
Find Deal
Thu, Dec 4 - Sun, Dec 7
Delta Logo
7:43 am - 1:22 pmTYS-STL
6h 39m1 stop
Delta Logo
9:10 am - 2:43 pmSTL-TYS
4h 33m1 stop
$294Delta
Find Deal
Wed, Oct 15 - Sun, Oct 19
Logo
4:15 pm - 1:32 pmTYS-STL
22h 17m3 stops
Logo
10:37 am - 10:16 amSTL-TYS
22h 39m2 stops
$323
Find Deal
Wed, Aug 13 - Sun, Aug 17
Logo
4:15 pm - 1:32 pmTYS-STL
22h 17m3 stops
Logo
10:37 am - 8:02 pmSTL-TYS
8h 25m1 stop
$336
Find Deal
Wed, Aug 13 - Sun, Aug 17
United Airlines Logo
7:25 pm - 2:19 pmTYS-STL
19h 54m2 stops
United Airlines Logo
6:15 am - 1:38 pmSTL-TYS
6h 23m1 stop
$404United Airlines
Find Deal
Fri, Sep 19 - Sun, Sep 21
United Airlines Logo
7:25 pm - 2:19 pmTYS-STL
19h 54m2 stops
United Airlines Logo
6:15 am - 1:38 pmSTL-TYS
6h 23m1 stop
$429United Airlines
Find Deal
Fri, Sep 19 - Sun, Sep 21

Delta flights from Knoxville to St. Louis

Our best Delta deals on Knoxville to St. Louis flight tickets
Delta
Sep 18
TYS10:24 amKnoxville McGhee Tyson
6h 41m
1 stop
STL4:05 pmLambert-St Louis
Sep 21
STL6:01 amLambert-St Louis
3h 55m
1 stop
TYS10:56 amKnoxville McGhee Tyson
$229
Find similar
Delta
Dec 4
TYS5:30 amKnoxville McGhee Tyson
3h 39m
1 stop
STL8:09 amLambert-St Louis
Dec 7
STL6:00 amLambert-St Louis
4h 05m
1 stop
TYS11:05 amKnoxville McGhee Tyson
$254
Find similar
Delta
Aug 8
TYS5:30 amKnoxville McGhee Tyson
3h 56m
1 stop
STL8:26 amLambert-St Louis
Aug 9
STL7:00 amLambert-St Louis
5h 54m
1 stop
TYS1:54 pmKnoxville McGhee Tyson
$269
Find similar

American Airlines flights from Knoxville to St. Louis

Our best American Airlines deals on Knoxville to St. Louis flight tickets
American Airlines
Aug 13
TYS10:10 amKnoxville McGhee Tyson
4h 41m
1 stop
STL1:51 pmLambert-St Louis
Aug 16
STL5:15 amLambert-St Louis
5h 15m
1 stop
TYS11:30 amKnoxville McGhee Tyson
$239
Find similar
American Airlines
Sep 19
TYS5:20 pmKnoxville McGhee Tyson
4h 50m
1 stop
STL9:10 pmLambert-St Louis
Sep 21
STL7:23 amLambert-St Louis
6h 20m
1 stop
TYS2:43 pmKnoxville McGhee Tyson
$249
Find similar
American Airlines
Aug 6
TYS12:20 pmKnoxville McGhee Tyson
7h 10m
1 stop
STL6:30 pmLambert-St Louis
Aug 15
STL5:15 amLambert-St Louis
7h 23m
1 stop
TYS1:38 pmKnoxville McGhee Tyson
$254
Find similar

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 July 31, 2025.
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

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Thu 9/25

8:40 pm-9:06 am

1 stop13h 26m

Lambert-St Louis

Sun 9/28

7:55 pm-7:45 pm

1 stop22h 50m

$225

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Thu 9/18

10:24 am-4:05 pm

1 stop6h 41m

Lambert-St Louis

Sun 9/21

6:01 am-10:56 am

1 stop3h 55m

$229

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Wed 8/13

10:10 am-1:51 pm

1 stop4h 41m

Lambert-St Louis

Sat 8/16

5:15 am-11:30 am

1 stop5h 15m

$239

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Fri 9/19

5:20 pm-9:10 pm

1 stop4h 50m

Lambert-St Louis

Sun 9/21

7:23 am-2:43 pm

1 stop6h 20m

$249

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Thu 12/4

5:30 am-8:09 am

1 stop3h 39m

Lambert-St Louis

Sun 12/7

6:00 am-11:05 am

1 stop4h 05m

$254

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Wed 10/15

7:43 am-1:22 pm

1 stop6h 39m

Lambert-St Louis

Sun 10/19

9:10 am-2:43 pm

1 stop4h 33m

$294

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Wed 8/13

4:15 pm-1:32 pm

3 stops22h 17m

Lambert-St Louis

Sun 8/17

10:37 am-10:16 am

2 stops22h 39m

$323

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Wed 8/13

4:15 pm-1:32 pm

3 stops22h 17m

Lambert-St Louis

Sun 8/17

10:37 am-8:02 pm

1 stop8h 25m

$336

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Fri 9/19

7:25 pm-2:19 pm

2 stops19h 54m

Lambert-St Louis

Sun 9/21

6:15 am-1:38 pm

1 stop6h 23m

$404

KnoxvilleSt. Louis

TYS - STL

TYSSTL

Knoxville McGhee Tyson

Fri 9/19

7:25 pm-2:19 pm

2 stops19h 54m

Lambert-St Louis

Sun 9/21

6:15 am-1:38 pm

1 stop6h 23m

$429

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, December 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 $283. The month of April is another great option to travel to St. Louis, with average flight prices from Knoxville averaging around $284.

What is the cheapest day to depart on your flight to St. Louis?

The cheapest day to depart on your flight to St. Louis is on a Wednesday when prices can be found for as low as $259. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Monday because tickets tend to average around $539. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.

What is the cheapest time of day to depart on your flight to St. Louis?

Flying to St. Louis from Knoxville at noon is the least expensive time of day to depart. momondo users have found prices as low as $265 when looking at flights departing at noon. In the morning is when there is more demand to fly to St. Louis, so prices are often more expensive at around $288 per ticket.

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

As of July 2025, prices for Knoxville to St. Louis flights are approximately 37% cheaper 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

Best Price Found

$117

Fastest flight time

3h 29m

Direct flights

None

Airports in St. Louis

1 airport
The best one-way flight to St. Louis from Knoxville in the past 72 hours is $117. The best round-trip flight deal from Knoxville to St. Louis found on momondo in the last 72 hours is $225.
The fastest flight from Knoxville to St. Louis takes 3h 29m
There are no direct flights from Knoxville to St. Louis. Popular non-direct route for this connection is Knoxville McGhee Tyson Airport - Lambert-St Louis Airport.
There is 1 airport near St. Louis: Lambert-St Louis (STL)
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 29m.

  • 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
7.2
10,000 reviews
Search American Airlines flights
United AirlinesPriceFrom $213Free CancellationRating
7.4
8,900 reviews
Search United Airlines flights
DeltaPriceFrom $228Free CancellationRating
8.0
7,981 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
Maryland Heights
Florissant
Fenton
Collinsville
O'Fallon
Alton
St. Peters
Farmington
Wentzville
Festus
Glencoe
Eureka
Edwardsville
Clayton
Shrewsbury
Grafton

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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