Latest deals
Insights
When to book
FAQs
Reviews
Price Alerts

Cheap flights from St. Louis to London from $332

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 4/15. 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
0 bags

Discover deals from 900+ travel sites with momondo.

Save money when you book flights with momondo

Big names and deals

Big names and deals

Search 100s of travel sites to compare prices.

Filter for what you want

Filter for what you want

Free Wi-Fi? Stopover? Instantly customize your results.

Trusted and free

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Price Alerts

Not ready to book? to track prices.
Search flight deals

Find the cheapest flights from St. Louis to London

Cheap round-trip flights

Enter your travel dates to find the best prices.
Multiple Airlines Logo
4:05 pm - 11:50 am
STL
-
LHR
13h 45m
1 stop
Multiple Airlines Logo
6:30 am - 1:25 pm
LHR
-
STL
12h 55m
1 stop
$643Multiple Airlines
Wed, Apr 1 - Wed, Apr 8
Multiple Airlines Logo
4:05 pm - 11:50 am
STL
-
LHR
13h 45m
1 stop
Multiple Airlines Logo
6:30 am - 1:25 pm
LHR
-
STL
12h 55m
1 stop
$644Multiple Airlines
Wed, Apr 15 - Fri, May 8
Lufthansa Logo
6:49 pm - 8:40 pm
STL
-
LHR
19h 51m
2 stops
Lufthansa Logo
9:00 am - 9:08 pm
LHR
-
STL
18h 08m
2 stops
$645Lufthansa
Tue, May 5 - Tue, May 19
Multiple Airlines Logo
4:05 pm - 6:35 am
STL
-
LHR
32h 30m
1 stop
Multiple Airlines Logo
6:30 am - 1:25 pm
LHR
-
STL
12h 55m
1 stop
$646Multiple Airlines
Sun, Apr 19 - Wed, Apr 29
Virgin Atlantic Logo
10:14 am - 6:50 am
STL
-
LHR
14h 36m
2 stops
Virgin Atlantic Logo
6:30 am - 5:53 pm
LHR
-
STL
16h 23m
2 stops
$648Virgin Atlantic
Wed, Mar 4 - Wed, Mar 11
United Airlines Logo
7:00 pm - 11:15 am
STL
-
LHR
11h 15m
1 stop
United Airlines Logo
1:25 pm - 2:42 pm
LHR
-
STL
30h 17m
2 stops
$650United Airlines
Wed, Mar 18 - Wed, Mar 25
Air Canada Logo
6:30 am - 6:30 am
STL
-
LHR
18h 00m
2 stops
Air Canada Logo
8:40 am - 8:05 pm
LHR
-
STL
17h 25m
2 stops
$651Air Canada
Wed, Apr 29 - Wed, May 6
Multiple Airlines Logo
10:00 am - 6:30 am
STL
-
LHR
14h 30m
2 stops
Multiple Airlines Logo
9:00 am - 9:08 pm
LHR
-
STL
18h 08m
2 stops
$652Multiple Airlines
Wed, Apr 1 - Wed, Apr 8
Multiple Airlines Logo
8:00 am - 6:30 am
STL
-
LHR
16h 30m
2 stops
Multiple Airlines Logo
10:50 am - 9:08 pm
LHR
-
STL
16h 18m
2 stops
$653Multiple Airlines
Wed, Apr 1 - Wed, Apr 8
Air Canada Logo
6:25 am - 7:10 am
STL
-
LHR
19h 45m
2 stops
Air Canada Logo
1:25 pm - 2:42 pm
LHR
-
STL
30h 17m
2 stops
$654Air Canada
Tue, Mar 10 - Wed, Mar 25

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
Feb 23
STL4:49 pmLambert-St Louis
32h 21m
2 stops
LHR7:10 amLondon Heathrow
Mar 4
LHR1:25 pmLondon Heathrow
15h 34m
2 stops
STL10:59 pmLambert-St Louis
$643
Air Canada
Feb 23
STL7:41 amLambert-St Louis
16h 49m
2 stops
LHR6:30 amLondon Heathrow
Mar 2
LHR1:45 pmLondon Heathrow
55h 44m
2 stops
STL3:29 pmLambert-St Louis
$645
Air Canada
Mar 10
STL6:25 amLambert-St Louis
19h 45m
2 stops
LHR7:10 amLondon Heathrow
Mar 25
LHR1:25 pmLondon Heathrow
30h 17m
2 stops
STL2:42 pmLambert-St Louis
$654

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
Feb 18
STL12:15 pmLambert-St Louis
14h 10m
2 stops
LHR8:25 amLondon Heathrow
Mar 3
LHR9:10 amLondon Heathrow
17h 55m
2 stops
STL9:05 pmLambert-St Louis
$650
United Airlines
May 11
STL1:00 pmLambert-St Louis
15h 00m
1 stop
LHR10:00 amLondon Heathrow
May 19
LHR7:25 amLondon Heathrow
19h 43m
2 stops
STL9:08 pmLambert-St Louis
$657
United Airlines
Feb 20
STL6:25 amLambert-St Louis
17h 30m
1 stop
LHR5:55 amLondon Heathrow
Feb 27
LHR6:50 amLondon Heathrow
15h 12m
2 stops
STL4:02 pmLambert-St Louis
$663

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 February 17, 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

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Wed 4/1

4:05 pm-11:50 am

1 stop13h 45m

London Heathrow

Wed 4/8

6:30 am-1:25 pm

1 stop12h 55m

$643

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Wed 4/15

4:05 pm-11:50 am

1 stop13h 45m

London Heathrow

Fri 5/8

6:30 am-1:25 pm

1 stop12h 55m

$644

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Tue 5/5

6:49 pm-8:40 pm

2 stops19h 51m

London Heathrow

Tue 5/19

9:00 am-9:08 pm

2 stops18h 08m

$645

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Sun 4/19

4:05 pm-6:35 am

1 stop32h 30m

London Heathrow

Wed 4/29

6:30 am-1:25 pm

1 stop12h 55m

$646

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Wed 3/4

10:14 am-6:50 am

2 stops14h 36m

London Heathrow

Wed 3/11

6:30 am-5:53 pm

2 stops16h 23m

$648

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Wed 3/18

7:00 pm-11:15 am

1 stop11h 15m

London Heathrow

Wed 3/25

1:25 pm-2:42 pm

2 stops30h 17m

$650

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Wed 4/29

6:30 am-6:30 am

2 stops18h 00m

London Heathrow

Wed 5/6

8:40 am-8:05 pm

2 stops17h 25m

$651

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Wed 4/1

10:00 am-6:30 am

2 stops14h 30m

London Heathrow

Wed 4/8

9:00 am-9:08 pm

2 stops18h 08m

$652

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Wed 4/1

8:00 am-6:30 am

2 stops16h 30m

London Heathrow

Wed 4/8

10:50 am-9:08 pm

2 stops16h 18m

$653

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Tue 3/10

6:25 am-7:10 am

2 stops19h 45m

London Heathrow

Wed 3/25

1:25 pm-2:42 pm

2 stops30h 17m

$654

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
1
2

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 $670. If you’re not able to fly to London Heathrow Airport in October, then April is your next best option. Flight prices from St. Louis to London Heathrow Airport during April average around $700.

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 $688. The most expensive day to fly to London Heathrow Airport is Saturday, with ticket prices averaging around $943.

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 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 $859 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 $786 on momondo.

What cabin class options are available on Lambert-St Louis to London Heathrow flights?

There are 3 cabin classes available to choose from on Lambert-St Louis to London Heathrow 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?

You could potentially save up to 2% on your flight if you consider stops on a St. Louis to London Heathrow Airport flight.

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

As of February 2026, prices for St. Louis to London Heathrow Airport flights are approximately 15% cheaper 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

$515

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 $515. The best round-trip flight deal from St. Louis to London Heathrow Airport found on momondo in the last 72 hours is $666.
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

  • 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
KLMPriceFrom $529Free CancellationRating
7.7
1,455 reviews
Search KLM flights
Air CanadaPriceFrom $572Free CancellationRating
7.1
10,725 reviews
Search Air Canada flights
British AirwaysPriceFrom $574Free CancellationRating
6.7
7,752 reviews
Search British Airways flights
DeltaPriceFrom $577Free CancellationRating
7.9
8,206 reviews
Search Delta flights
IberiaPriceFrom $580Free CancellationRating
7.0
3,116 reviews
Search Iberia flights
United AirlinesPriceFrom $580Free CancellationRating
7.4
9,308 reviews
Search United Airlines flights
American AirlinesPriceFrom $596Free CancellationRating
7.2
11,294 reviews
Search American Airlines flights
Scandinavian AirlinesPriceFrom $602Free CancellationRating
7.3
1,685 reviews
Search Scandinavian Airlines flights
Virgin AtlanticPriceFrom $615Free CancellationRating
7.5
678 reviews
Search Virgin Atlantic flights
LufthansaPriceFrom $668Free CancellationRating
6.8
7,786 reviews
Search Lufthansa flights

Traveling to a place near London?

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

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

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.
Start using Trips
Find my bookings

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.
1 adult
Thu 3/19
Thu 3/26
By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to London

Popular cities in the United Kingdom

Popular flights according to clicks in the last 7 days on momondo
Flights to London Gatwick Airportfrom $382
Flights to London City Airportfrom $517
Flights to London Stansted Airportfrom $354
Flights to London Luton Airportfrom $348
Flights to Glasgow Intl Airportfrom $378
Flights to Belfast Intl Airportfrom $497
Flights to London Southend Airportfrom $484
Flights to Belfast City Airportfrom $561