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$280+ Cheap flights from St. Louis (STL) to Heathrow (LHR)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 10/17. Fares are subject to change and may not be available on all flights or dates of travel.
STL — LHR
Oct 17 — Oct 241
Fri 10/17
Fri 10/24
1 adult, Economy
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Cheapflights Tip: The best prices from Lambert-St Louis to London Heathrow are usually found in October or September, booked 34 days in advance, depart on a Thursday or Tuesday and return on a Thursday

Cheap flight deals from St. Louis to Heathrow

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Heathrow (LHR). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated September 17, 2025.

Round-trip from

$530
(Delta)

One-way from

$280
(Kiwi.com)

Popular in

June

Cheapest in

October

Average price

$779
From Lambert-St Louis to London Heathrow
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One-way flight from Lambert-St Louis to London Heathrow
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Highest demand for flights based on searches. 17% potential increase in price ($194 potential increase over avg. RT price).
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Cheapest flight prices on average. 3% potential price decrease ($32 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Find flight deals from St. Louis to Heathrow

Cheapest flights from St. Louis to Heathrow
Explore the most affordable flight options available from St. Louis to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 17, 2025.

This Delta deal was found by Cheapflights users on 9/14. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/1410:45 amSTL - LHR
2 stops16h 05mDelta
Wed 10/226:30 amLHR - STL
2 stops16h 59mDelta
Deal found 9/14$530
This Air Canada deal was found by Cheapflights users on 9/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/114:05 pmSTL - LHR
2 stops33h 05mAir Canada
Tue 11/181:25 pmLHR - STL
2 stops32h 04mAir Canada
Deal found 9/16$531
This Delta deal was found by Cheapflights users on 9/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/28:53 amSTL - LHR
1 stop16h 12mDelta
Tue 11/1110:45 amLHR - STL
1 stop13h 50mDelta
Deal found 9/15$532
This Air Canada deal was found by Cheapflights users on 9/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/1810:00 amSTL - LHR
2 stops14h 30mAir Canada
Wed 11/266:00 pmLHR - STL
1 stop27h 29mAir Canada
Deal found 9/16$535
This United Airlines deal was found by Cheapflights users on 9/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/83:19 pmSTL - LHR
2 stops14h 01mUnited Airlines
Tue 12/168:00 amLHR - STL
2 stops17h 48mUnited Airlines
Deal found 9/16$543
This Delta deal was found by Cheapflights users on 9/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/191:55 pmSTL - LHR
2 stops13h 05mDelta
Fri 12/59:00 amLHR - STL
2 stops18h 03mDelta
Deal found 9/15$556
This United Airlines deal was found by Cheapflights users on 9/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/194:05 pmSTL - LHR
1 stop10h 25mUnited Airlines
Sun 11/239:00 amLHR - STL
2 stops37h 35mUnited Airlines
Deal found 9/15$561
This Air Canada deal was found by Cheapflights users on 9/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/111:30 pmSTL - LHR
1 stop11h 00mAir Canada
Tue 10/216:50 amLHR - STL
2 stops14h 28mAir Canada
Deal found 9/15$563
This United Airlines deal was found by Cheapflights users on 9/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/55:15 amSTL - LHR
1 stop25h 05mUnited Airlines
Sun 10/123:50 pmLHR - STL
1 stop33h 58mUnited Airlines
Deal found 9/15$566
This Air Canada deal was found by Cheapflights users on 9/14. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/51:30 pmSTL - LHR
1 stop11h 00mAir Canada
Sun 10/129:30 amLHR - STL
1 stop16h 27mAir Canada
Deal found 9/14$567

Cheapflights Fare Finder

 
Customize your flight search to find flights from St. Louis to Heathrow 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, Cheapflights users made 2,558,603 searches. Data last updated September 17, 2025.
Use the filters below to find and compare flights from St. Louis to London Heathrow Airport that are best for you.

Fly from

St. Louis

Fly to

Heathrow

Route

Depart

Return

Price

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

6:30 am-5:29 pm

2 stops16h 59m

$530

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Wed 1/21

4:05 pm-8:30 am

1 stop10h 25m

London Heathrow

Thu 1/29

6:00 pm-3:29 pm

1 stop27h 29m

$531

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Tue 11/11

4:05 pm-7:10 am

2 stops33h 05m

London Heathrow

Tue 11/18

1:25 pm-3:29 pm

2 stops32h 04m

$531

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Mon 12/8

1:00 pm-5:55 am

1 stop10h 55m

London Heathrow

Tue 12/16

10:25 am-5:03 pm

1 stop12h 38m

$532

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Sun 11/2

8:53 am-7:05 am

1 stop16h 12m

London Heathrow

Tue 11/11

10:45 am-6:35 pm

1 stop13h 50m

$532

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Mon 1/19

11:51 am-9:00 am

1 stop15h 09m

London Heathrow

Wed 1/28

11:45 am-8:39 pm

2 stops14h 54m

$534

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Tue 1/20

10:00 am-9:00 am

1 stop17h 00m

London Heathrow

Wed 1/28

11:45 am-8:39 pm

2 stops14h 54m

$534

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Mon 1/19

7:30 am-7:50 am

1 stop18h 20m

London Heathrow

Thu 1/29

6:30 am-4:50 pm

2 stops16h 20m

$534

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Wed 1/21

10:45 am-8:45 am

1 stop16h 00m

London Heathrow

Tue 1/27

11:45 am-8:39 pm

2 stops14h 54m

$534

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Mon 1/19

10:00 am-7:50 am

1 stop15h 50m

London Heathrow

Tue 1/27

11:45 am-8:39 pm

2 stops14h 54m

$534

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/15

Showing 1-10 of 22 results
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Best time to book a flight from St. Louis to Heathrow

Have a flexible travel schedule? Discover the best time to fly to Heathrow from St. Louis with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from St. Louis to London Heathrow Airport

How far ahead should I book a flight from St. Louis to London Heathrow Airport?

Use this chart to determine the optimal time to book a round-trip flight from St. Louis to Heathrow. Price data was last updated on September 12, 2025.

To ensure you get the cheapest price possible for a flight from St. Louis to London Heathrow Airport, you should look to book at least 34 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

What is the cheapest month to book a flight from St. Louis to London Heathrow Airport?

Currently, November is the cheapest month in which you can book a flight from St. Louis to London Heathrow Airport (average of $661). Flying from St. Louis to London Heathrow Airport in June is currently the most expensive (average of $1,097). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from STL to LHR?

Find hourly flight availability from St. Louis to Heathrow. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated September 17, 2025.

One of the essential ways to save on airfare from St. Louis to London Heathrow Airport is to remain as flexible as possible. Flights that are in the morning tend to be the most expensive. A flight in the evening could potentially save you up to 11% on airfare.

Reviews of airlines servicing Heathrow

Get insights into the airlines that provide service to Heathrow. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Heathrow. Reviews last updated September 17, 2025.
Get a feel of what it's like to fly with United Airlines, American Airlines, and Air Canada from St. Louis to London Heathrow Airport by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
United Airlines
7.4
Good
8,926 reviews

Comfort

7.3

Crew

8.1

Food

6.6

Overall

7.4

Entertainment

7.1

Boarding

7.7

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??
United Airlines
7.4
Good
8,926 reviews
United Airlines
7.4
Good
8,926 reviews

Comfort

7.3

Crew

8.1

Food

6.6

Overall

7.4

Entertainment

7.1

Boarding

7.7

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??
American Airlines
7.2
Good
10,000 reviews
United Airlines
7.4
Good
8,926 reviews

Comfort

7.3

Crew

8.1

Food

6.6

Overall

7.4

Entertainment

7.1

Boarding

7.7

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??
Air Canada
7.1
Good
10,000 reviews
United Airlines
7.4
Good
8,926 reviews

Comfort

7.3

Crew

8.1

Food

6.6

Overall

7.4

Entertainment

7.1

Boarding

7.7

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??
Iberia
7.0
Good
2,925 reviews
United Airlines
7.4
Good
8,926 reviews

Comfort

7.3

Crew

8.1

Food

6.6

Overall

7.4

Entertainment

7.1

Boarding

7.7

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??
British Airways
6.7
Okay
7,367 reviews
United Airlines
7.4
Good
8,926 reviews

Comfort

7.3

Crew

8.1

Food

6.6

Overall

7.4

Entertainment

7.1

Boarding

7.7

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Heathrow. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly from for flights from St. Louis to London Heathrow?

    Located just 12.7 mi from the city center, Lambert-St Louis is the airport most travelers will use when flying to London Heathrow from St. Louis. Booking flights from Lambert-St Louis (STL) to London Heathrow should be relatively easy as there are 0 daily outbound flights to London Heathrow from 10 different airlines.

  • How long is the flight from St. Louis to London Heathrow Airport?

    Delta, Air Canada, and United Airlines can get you from St. Louis to London Heathrow Airport in just under 10h 25m. Your travel time can differ by up to 5h 40m. Airlines will cover a distance of 4186 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines flying from St. Louis to London Heathrow Airport round-trip?

    According to our current data, KLM ($530), United Airlines ($580), and British Airways ($590) offers the cheapest pricing from St. Louis to London Heathrow Airport. KLM is 42% cheaper than the average price of flights available within the next 90 days to this destination.

  • Can I find deals for flights from St. Louis to Heathrow that include hotel bookings?

    Yes. In addition to deals on St. Louis to Heathrow flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from St. Louis to Heathrow?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from St. Louis to Heathrow.

  • Can I find deals for business class flights from St. Louis to Heathrow?

    Yes. Cheapflights offers flight deals from St. Louis to Heathrow by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from St. Louis to London Heathrow Airport?

    Currently, November is the cheapest month in which you can book a flight from St. Louis to London Heathrow Airport (average of $661). Flying from St. Louis to London Heathrow Airport in June is currently the most expensive (average of $1,097). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near London Heathrow Airport?

Book flights to London Heathrow Airport if you plan to visit one of these locations
Hounslow
Hayes
Southend-on-Sea
Harrow
Canterbury
Croydon
Eastleigh
Dartford
Dover
Winchester
Orpington
Northampton
Gatwick
Borehamwood
Broadway
Aylesbury
Bedford
Wembley
Folkestone
Chichester

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Top 10 airlines flying from St. Louis to Heathrow

Discover the top 10 airlines that operate flights from St. Louis to Heathrow. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated September 17, 2025.
AirlineCheapestAverageFlexibilityOn-time
KLMCheapest$530Average$736FlexibilityNo cancel feeOn-time75%
United AirlinesCheapest$580Average$884FlexibilityNo cancel feeOn-time69%
British AirwaysCheapest$590Average$942FlexibilityNo cancel feeOn-time70%
DeltaCheapest$631Average$947FlexibilityNo cancel feeOn-timeN/A
Air CanadaCheapest$634Average$942FlexibilityNo cancel feeOn-time67%
American AirlinesCheapest$637Average$964FlexibilityNo cancel feeOn-time71%
IberiaCheapest$666Average$978FlexibilityNo cancel feeOn-time77%
Scandinavian AirlinesCheapest$669Average$1,102FlexibilityNo cancel feeOn-time77%
LufthansaCheapest$670Average$888FlexibilityNo cancel feeOn-time76%
Virgin AtlanticCheapest$727Average$913FlexibilityNo cancel feeOn-time72%

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