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Cheap flights from St. Louis to London from $275

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to London departing on 10/3. 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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Find the cheapest flights from St. Louis to London

Cheap round-trip flights

United Airlines Logo
6:43 pm - 11:15 amSTL-LHR
10h 32m1 stop
United Airlines Logo
6:00 pm - 3:29 pmLHR-STL
27h 29m1 stop
$528United Airlines
Find Deal
Tue, Nov 18 - Thu, Nov 27
Air Canada Logo
12:25 pm - 9:35 amSTL-LHR
15h 10m2 stops
Air Canada Logo
3:50 pm - 10:49 amLHR-STL
24h 59m2 stops
$529Air Canada
Find Deal
Mon, Oct 6 - Wed, Oct 22
Delta Logo
10:45 am - 8:50 amSTL-LHR
16h 05m2 stops
Delta Logo
8:40 am - 8:23 pmLHR-STL
17h 43m2 stops
$530Delta
Find Deal
Tue, Oct 14 - Wed, Oct 22
Delta Logo
12:14 pm - 7:05 amSTL-LHR
12h 51m1 stop
Delta Logo
8:55 am - 4:33 pmLHR-STL
13h 38m1 stop
$532Delta
Find Deal
Sun, Nov 2 - Tue, Nov 11
Iberia Logo
1:30 pm - 7:00 amSTL-LHR
11h 30m1 stop
Iberia Logo
7:40 pm - 9:57 amLHR-STL
20h 17m2 stops
$561Iberia
Find Deal
Thu, Jan 15 - Mon, Jan 26
Iberia Logo
10:44 am - 7:50 amSTL-LHR
15h 06m1 stop
Iberia Logo
3:00 pm - 10:34 pmLHR-STL
13h 34m1 stop
$576Iberia
Find Deal
Mon, Nov 17 - Sun, Nov 23
British Airways Logo
8:03 pm - 12:15 pmSTL-LHR
10h 12m1 stop
British Airways Logo
8:20 am - 4:17 pmLHR-STL
13h 57m1 stop
$582British Airways
Find Deal
Sun, Oct 5 - Sun, Oct 12
Scandinavian Airlines Logo
11:44 am - 5:40 pmSTL-LHR
23h 56m2 stops
Scandinavian Airlines Logo
6:40 am - 9:58 pmLHR-STL
21h 18m2 stops
$604Scandinavian Airlines
Find Deal
Sat, Nov 15 - Sat, Nov 22
British Airways Logo
1:03 pm - 10:20 amSTL-LHR
15h 17m1 stop
British Airways Logo
8:20 am - 6:28 pmLHR-STL
16h 08m1 stop
$610British Airways
Find Deal
Wed, Sep 24 - Sun, Sep 28
Scandinavian Airlines Logo
3:59 pm - 4:00 pmSTL-LHR
18h 01m2 stops
Scandinavian Airlines Logo
6:40 pm - 11:41 pmLHR-STL
34h 01m2 stops
$616Scandinavian Airlines
Find Deal
Tue, Oct 21 - Sun, Oct 26

United Airlines flights from St. Louis to London Heathrow Airport

Our best United Airlines deals on St. Louis to London Heathrow Airport flight tickets
United Airlines
Nov 18
STL6:43 pmLambert-St Louis
10h 32m
1 stop
LHR11:15 amLondon Heathrow
Nov 27
LHR6:00 pmLondon Heathrow
27h 29m
1 stop
STL3:29 pmLambert-St Louis
$528
Find similar
United Airlines
Oct 27
STL8:00 amLambert-St Louis
22h 15m
1 stop
LHR11:15 amLondon Heathrow
Nov 3
LHR2:30 pmLondon Heathrow
37h 24m
2 stops
STL9:54 pmLambert-St Louis
$560
Find similar
United Airlines
Oct 29
STL4:50 pmLambert-St Louis
16h 55m
1 stop
LHR2:45 pmLondon Heathrow
Nov 5
LHR6:50 amLondon Heathrow
16h 49m
2 stops
STL5:39 pmLambert-St Louis
$562
Find similar

Air Canada flights from St. Louis to London Heathrow Airport

Our best Air Canada deals on St. Louis to London Heathrow Airport flight tickets
Air Canada
Oct 6
STL12:25 pmLambert-St Louis
15h 10m
2 stops
LHR9:35 amLondon Heathrow
Oct 22
LHR3:50 pmLondon Heathrow
24h 59m
2 stops
STL10:49 amLambert-St Louis
$529
Find similar
Air Canada
Sep 21
STL9:15 amLambert-St Louis
15h 15m
2 stops
LHR6:30 amLondon Heathrow
Oct 1
LHR9:30 amLondon Heathrow
16h 08m
2 stops
STL7:38 pmLambert-St Louis
$530
Find similar
Air Canada
Nov 11
STL4:05 pmLambert-St Louis
33h 05m
2 stops
LHR7:10 amLondon Heathrow
Nov 18
LHR1:25 pmLondon Heathrow
32h 04m
2 stops
STL3:29 pmLambert-St Louis
$531
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from St. Louis to London Heathrow Airport 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 September 14, 2025.
Use the filters below to find and compare flights from St. Louis to London Heathrow Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Tue 11/18

6:43 pm-11:15 am

1 stop10h 32m

London Heathrow

Thu 11/27

6:00 pm-3:29 pm

1 stop27h 29m

$528

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Mon 10/6

12:25 pm-9:35 am

2 stops15h 10m

London Heathrow

Wed 10/22

3:50 pm-10:49 am

2 stops24h 59m

$529

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Tue 10/14

10:45 am-8:50 am

2 stops16h 05m

London Heathrow

Wed 10/22

8:40 am-8:23 pm

2 stops17h 43m

$530

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Sun 11/2

12:14 pm-7:05 am

1 stop12h 51m

London Heathrow

Tue 11/11

8:55 am-4:33 pm

1 stop13h 38m

$532

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Thu 1/15

1:30 pm-7:00 am

1 stop11h 30m

London Heathrow

Mon 1/26

7:40 pm-9:57 am

2 stops20h 17m

$561

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Mon 11/17

10:44 am-7:50 am

1 stop15h 06m

London Heathrow

Sun 11/23

3:00 pm-10:34 pm

1 stop13h 34m

$576

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Sun 10/5

8:03 pm-12:15 pm

1 stop10h 12m

London Heathrow

Sun 10/12

8:20 am-4:17 pm

1 stop13h 57m

$582

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Sat 11/15

11:44 am-5:40 pm

2 stops23h 56m

London Heathrow

Sat 11/22

6:40 am-9:58 pm

2 stops21h 18m

$604

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Wed 9/24

1:03 pm-10:20 am

1 stop15h 17m

London Heathrow

Sun 9/28

8:20 am-6:28 pm

1 stop16h 08m

$610

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Tue 10/21

3:59 pm-4:00 pm

2 stops18h 01m

London Heathrow

Sun 10/26

6:40 pm-11:41 pm

2 stops34h 01m

$616

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 London from

How to get the cheapest flight ticket from St. Louis to London Heathrow Airport

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 St. Louis and London Heathrow Airport?

What is the cheapest month to fly to London Heathrow Airport?

The month of October is, on average, the cheapest month to fly to London Heathrow Airport from St. Louis, with most prices found around $739. If you’re not able to fly to London Heathrow Airport in October, then September is your next best option. Flight prices from St. Louis to London Heathrow Airport during September average around $779.

What is the cheapest day to depart on your flight to London Heathrow Airport?

Our data shows that Thursday is the least expensive day to fly to London Heathrow Airport. Tickets to fly out on this day can be as low as $906. The most expensive day to fly to London Heathrow Airport is Friday, with ticket prices averaging around $1,015.

What is the cheapest time of day to depart on your flight to London Heathrow Airport?

According to our data, the cheapest time of day to fly to London Heathrow Airport is in the evening. momondo users have found flights departing from St. Louis to London Heathrow Airport in the evening for as low as $895. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights in the morning are often more expensive with an average ticket price of $996.

How far in advance should I book a flight to London Heathrow Airport?

You are more likely to see cheaper flights to London Heathrow Airport from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to London Heathrow Airport for around $920 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to London Heathrow Airport from St. Louis for as low as $751 on momondo.

Can stopping save me money on St. Louis to London Heathrow Airport flights?

You could potentially save up to 5% on your flight if you consider stops on a St. Louis to London Heathrow Airport flight.

When to book flights from St. Louis to London Heathrow Airport

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

Cheap St. Louis to London Heathrow Airport (STL to LHR) flight deals and tips

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

Direct flights

None
There are no direct flights from St. Louis to London Heathrow Airport. There are no popular flight routes from St. Louis to London Heathrow Airport.
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  • How far is Lambert-St Louis to London Heathrow by plane?

    Lambert-St Louis and London Heathrow are 4185.8 mi apart from one another. By plane, this route typically takes 10h 12m.

  • When did momondo last update prices for flights from Lambert-St Louis Airport to London Heathrow Airport?

    Prices for flights from Lambert-St Louis Airport to London Heathrow Airport were last updated today.

  • How many operators does momondo search for flights from Lambert-St Louis Airport to London Heathrow Airport?

  • How old do you have to be to fly from Lambert-St Louis Airport to London Heathrow 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 Lambert-St Louis Airport to London Heathrow Airport.

  • What documentation or ID do you need to fly to London Heathrow Airport?

    The necessary travel and health documents for your London Heathrow Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

  • What is the most popular airline from St. Louis to London Heathrow Airport?

Best airlines flying from St. Louis to London Heathrow Airport

Compare and see reviews for airlines that fly from St. Louis to London Heathrow Airport with momondo
Airline
Rating
Free Cancellation
Price
KLMPriceFrom $530Free CancellationRating
7.8
1,385 reviews
Search KLM flights
DeltaPriceFrom $631Free CancellationRating
7.9
7,956 reviews
Search Delta flights
British AirwaysPriceFrom $631Free CancellationRating
6.6
7,361 reviews
Search British Airways flights
American AirlinesPriceFrom $638Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
Scandinavian AirlinesPriceFrom $669Free CancellationRating
7.4
1,484 reviews
Search Scandinavian Airlines flights
United AirlinesPriceFrom $669Free CancellationRating
7.4
8,931 reviews
Search United Airlines flights
LufthansaPriceFrom $670Free CancellationRating
6.8
7,409 reviews
Search Lufthansa flights
IberiaPriceFrom $671Free CancellationRating
7.0
2,928 reviews
Search Iberia flights
Air CanadaPriceFrom $691Free CancellationRating
7.1
10,000 reviews
Search Air Canada flights
Virgin AtlanticPriceFrom $727Free CancellationRating
7.4
664 reviews
Search Virgin Atlantic flights

Traveling to a place near London?

Book flights to London if you plan to visit one of these locations
Gatwick
Hounslow
Dover
Luton
Slough
Milton Keynes
Hayes
Guildford
Dartford
Crawley
Stansted
Chelmsford
Salisbury
Brentwood
Ilford
Folkestone
Colchester
Swindon
Stratford-upon-Avon
Watford

Why use momondo?

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

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to London from St. Louis.

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

Flights from St. Louis to London with flexible booking policies can be found by using the search form above and then selecting our dedicated flexible booking filter, which will highlight only the flights where this policy is applied.

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

Once all potential St. Louis to London flight options are in front of you, momondo lets you sort and filter flights based on preferences such as airline, price and flight times amongst many other options.

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

Yes momondo offers price alerts on flights to London from St. Louis. After performing a search on this page you should be able to see the price alert set up feature. Simply provide a valid email address and momondo will instantly alert you when prices change.

An easier way to manage your London Heathrow Airport trip

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