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Cheap flights from St. Louis to London from $320

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 7/26. 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
0 bags

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from St. Louis to London

Cheap round-trip flights

Enter your travel dates to find the best prices.
Scandinavian Airlines Logo
11:42 am - 4:00 pm
STL
-
LHR
22h 18m
2 stops
Scandinavian Airlines Logo
6:40 pm - 9:38 pm
LHR
-
STL
32h 58m
2 stops
$890Scandinavian Airlines
Sat, May 2 - Fri, May 8
British Airways Logo
2:35 pm - 8:05 am
STL
-
LHR
11h 30m
1 stop
British Airways Logo
8:55 am - 4:41 pm
LHR
-
STL
13h 46m
1 stop
$892British Airways
Sun, Jul 19 - Wed, Aug 19
Iberia Logo
9:40 pm - 11:40 am
STL
-
LHR
8h 00mnonstop
Iberia Logo
12:55 pm - 8:26 pm
LHR
-
STL
13h 31m
1 stop
$893Iberia
Sun, Jul 19 - Wed, Aug 19
Iberia Logo
1:09 pm - 10:35 am
STL
-
LHR
15h 26m
2 stops
Iberia Logo
10:05 am - 8:26 pm
LHR
-
STL
16h 21m
1 stop
$905Iberia
Sun, Jul 19 - Wed, Aug 19
Virgin Atlantic Logo
3:40 pm - 11:20 am
STL
-
LHR
13h 40m
2 stops
Virgin Atlantic Logo
11:20 am - 8:31 pm
LHR
-
STL
15h 11m
2 stops
$973Virgin Atlantic
Sun, Jul 19 - Wed, Aug 19
Multiple Airlines Logo
2:15 pm - 7:55 pm
STL
-
LHR
23h 40m
3 stops
Multiple Airlines Logo
9:05 pm - 8:25 pm
LHR
-
STL
29h 20m
3 stops
$989Multiple Airlines
Tue, May 5 - Tue, May 12
Aer Lingus Logo
12:27 pm - 9:05 am
STL
-
LHR
14h 38m
2 stops
Aer Lingus Logo
12:00 pm - 10:19 pm
LHR
-
STL
16h 19m
2 stops
$1,049Aer Lingus
Tue, May 5 - Tue, May 19
Aer Lingus Logo
12:59 pm - 11:10 am
STL
-
LHR
16h 11m
2 stops
Aer Lingus Logo
12:00 pm - 11:56 pm
LHR
-
STL
17h 56m
2 stops
$1,050Aer Lingus
Tue, Apr 28 - Tue, May 19
Aer Lingus Logo
12:27 pm - 9:05 am
STL
-
LHR
14h 38m
2 stops
Aer Lingus Logo
7:35 pm - 11:46 pm
LHR
-
STL
34h 11m
2 stops
$1,063Aer Lingus
Mon, Apr 27 - Mon, May 4
Virgin Atlantic Logo
5:36 pm - 1:05 pm
STL
-
LHR
13h 29m
1 stop
Virgin Atlantic Logo
11:15 am - 5:46 pm
LHR
-
STL
12h 31m
1 stop
$1,071Virgin Atlantic
Mon, May 18 - Tue, May 26

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Aer Lingus flights from St. Louis to London Heathrow Airport

Our best Aer Lingus deals on St. Louis to London Heathrow Airport flight tickets
Aer Lingus
May 5
STL12:27 pmLambert-St Louis
14h 38m
2 stops
LHR9:05 amLondon Heathrow
May 19
LHR12:00 pmLondon Heathrow
16h 19m
2 stops
STL10:19 pmLambert-St Louis
$1,049
Aer Lingus
Apr 28
STL12:59 pmLambert-St Louis
16h 11m
2 stops
LHR11:10 amLondon Heathrow
May 19
LHR12:00 pmLondon Heathrow
17h 56m
2 stops
STL11:56 pmLambert-St Louis
$1,050
Aer Lingus
Apr 27
STL12:27 pmLambert-St Louis
14h 38m
2 stops
LHR9:05 amLondon Heathrow
May 4
LHR7:35 pmLondon Heathrow
34h 11m
2 stops
STL11:46 pmLambert-St Louis
$1,063

British Airways flights from St. Louis to London Heathrow Airport

Our best British Airways deals on St. Louis to London Heathrow Airport flight tickets
British Airways
Jul 19
STL2:35 pmLambert-St Louis
11h 30m
1 stop
LHR8:05 amLondon Heathrow
Aug 19
LHR8:55 amLondon Heathrow
13h 46m
1 stop
STL4:41 pmLambert-St Louis
$892
British Airways
May 19
STL11:45 amLambert-St Louis
14h 15m
1 stop
LHR8:00 amLondon Heathrow
May 26
LHR8:55 amLondon Heathrow
13h 23m
1 stop
STL4:18 pmLambert-St Louis
$1,116

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 April 24, 2026.
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

Cheapest round-trip

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Sat 5/2

11:42 am-4:00 pm

2 stops22h 18m

London Heathrow

Fri 5/8

6:40 pm-9:38 pm

2 stops32h 58m

$890

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Sun 7/19

2:35 pm-8:05 am

1 stop11h 30m

London Heathrow

Wed 8/19

8:55 am-4:41 pm

1 stop13h 46m

$892
Quickest round-trip

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Sun 7/19

9:40 pm-11:40 am

Nonstop8h 00m

London Heathrow

Wed 8/19

12:55 pm-8:26 pm

1 stop13h 31m

$893

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Sun 7/19

1:09 pm-10:35 am

2 stops15h 26m

London Heathrow

Wed 8/19

10:05 am-8:26 pm

1 stop16h 21m

$905

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Sun 7/19

3:40 pm-11:20 am

2 stops13h 40m

London Heathrow

Wed 8/19

11:20 am-8:31 pm

2 stops15h 11m

$973

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Tue 5/5

2:15 pm-7:55 pm

3 stops23h 40m

London Heathrow

Tue 5/12

9:05 pm-8:25 pm

3 stops29h 20m

$989

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Tue 5/5

12:27 pm-9:05 am

2 stops14h 38m

London Heathrow

Tue 5/19

12:00 pm-10:19 pm

2 stops16h 19m

$1,049

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Tue 4/28

12:59 pm-11:10 am

2 stops16h 11m

London Heathrow

Tue 5/19

12:00 pm-11:56 pm

2 stops17h 56m

$1,050

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Mon 4/27

12:27 pm-9:05 am

2 stops14h 38m

London Heathrow

Mon 5/4

7:35 pm-11:46 pm

2 stops34h 11m

$1,063

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Mon 5/18

5:36 pm-1:05 pm

1 stop13h 29m

London Heathrow

Tue 5/26

11:15 am-5:46 pm

1 stop12h 31m

$1,071

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 $658. If you’re not able to fly to London Heathrow Airport in October, then November is your next best option. Flight prices from St. Louis to London Heathrow Airport during November average around $707.

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

Our data shows that Monday is the least expensive day to fly to London Heathrow Airport. Tickets to fly out on this day can be as low as $736. The most expensive day to fly to London Heathrow Airport is Saturday, with ticket prices averaging around $1,101.

What is the cheapest Lambert-St Louis to London Heathrow flight route?

Fly from Lambert-St Louis to London Heathrow for the best Lambert-St Louis - London Heathrow flight prices

How far in advance should I book a flight from St. Louis 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 $848 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 $720 on momondo.

What cabin class options are available on St. Louis to London Heathrow Airport flights?

There are 3 cabin classes available to choose from on St. Louis to London Heathrow Airport flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

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

No. A direct flight is the cheapest option for a flight between St. Louis to London Heathrow Airport.

How have St. Louis to London Heathrow Airport flight prices changed over time?

As of April 2026, prices for St. Louis to London Heathrow Airport flights are approximately 27% more expensive when compared to flights at the same time last year.

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

Best Price Found

$511

Fastest flight time

8h 00m

Direct flights

Mon, Wed, Thu and Sat
The best one-way flight to London Heathrow Airport from St. Louis in the past 72 hours is $511. The best round-trip flight deal from St. Louis to London Heathrow Airport found on momondo in the last 72 hours is $986.
The fastest flight from St. Louis to London Heathrow Airport takes 8h 00m
Direct flights go from St. Louis to London Heathrow Airport on Monday, Wednesday, Thursday and Saturday. There are no airlines offering direct flights.
Search flight deals

Frequently asked questions about flying from St. Louis to London Heathrow Airport

  • 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 8h 00m.

  • 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 plane model from St. Louis to London Heathrow Airport?

  • 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
DeltaPriceFrom $483Free CancellationRating
7.9
8,457 reviews
Search Delta flights
KLMPriceFrom $529Free CancellationRating
7.8
1,508 reviews
Search KLM flights
British AirwaysPriceFrom $538Free CancellationRating
6.7
7,911 reviews
Search British Airways flights
American AirlinesPriceFrom $563Free CancellationRating
7.1
11,670 reviews
Search American Airlines flights
Air CanadaPriceFrom $572Free CancellationRating
7.1
10,965 reviews
Search Air Canada flights
IberiaPriceFrom $577Free CancellationRating
7.0
3,195 reviews
Search Iberia flights
United AirlinesPriceFrom $580Free CancellationRating
7.4
9,649 reviews
Search United Airlines flights
LufthansaPriceFrom $635Free CancellationRating
6.8
7,948 reviews
Search Lufthansa flights

  • American Airlines Flights From St. Louis to London Heathrow Airport

    American Airlines is one of the most popular airlines flying from St. Louis to London Heathrow Airport, operating 3 flights/week on average for this route. A good American Airlines flight deal for St. Louis to London Heathrow Airport starts from $563 round-trip, up to an average price of $864. Our users have rated American Airlines at 7.1/10.

  • Iberia Flights From St. Louis to London Heathrow Airport

    Iberia is also a popular choice for this route. Iberia flight deals for St. Louis to London Heathrow Airport start from as low as $577 round-trip, depending on your selected dates, with average Iberia deals seen on momondo around $898. Iberia operates 3 flights to London Heathrow Airport from St. Louis in an average week. Users have rated it 7.0/10 across 3,196 reviews.

Traveling to a place near London?

Book flights to London if you plan to visit one of these locations
Hounslow
Gatwick
Milton Keynes
Dover
Luton
Hayes
Stratford-upon-Avon
Crawley
Slough
Wembley
Stansted
Watford
Croydon
Brentwood
Dartford
Cobham
Folkestone
Guildford
Romford
Harrow

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.

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