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Heathrow

$278+ 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 10/20. Fares are subject to change and may not be available on all flights or dates of travel.
STL — LHR
Aug 23 — Aug 301
Sat 8/23
Sat 8/30
1 adult, Economy
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Cheapflights Tip: The best prices from Lambert-St Louis to London Heathrow are usually found in August or October, 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 August 18, 2025.

Round-trip from

$531
(Cheapflightsfares)

One-way from

$278
(Kiwi.com)

Popular in

June

Cheapest in

August

Average price

$786
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 ($190 potential increase over avg. RT price).
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Cheapest flight prices on average. 3% potential price decrease ($31 potential savings vs. average RT price).
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Average for round-trip flights in August 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 August 18, 2025.

This Scandinavian Airlines deal was found by Cheapflights users on 8/18. 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 Scandinavian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/73:59 pmSTL - LHR
2 stops18h 01mScandinavian Airlines
Sun 11/96:40 amLHR - STL
3 stops22h 59mScandinavian Airlines
Deal found 8/18$635
This Cheapflightsfares deal was found by Cheapflights users on 8/18. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/41:21 pmSTL - LHR
2 stops26h 19mScandinavian Airlines
Tue 9/166:40 amLHR - STL
2 stops21h 20mScandinavian Airlines
Deal found 8/18$674
This Scandinavian Airlines deal was found by Cheapflights users on 8/18. 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 Scandinavian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/21:26 pmSTL - LHR
2 stops22h 14mScandinavian Airlines
Thu 10/96:40 amLHR - STL
2 stops23h 01mScandinavian Airlines
Deal found 8/18$699
This Scandinavian Airlines deal was found by Cheapflights users on 8/17. 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 Scandinavian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/113:59 pmSTL - LHR
2 stops19h 41mScandinavian Airlines
Sat 10/256:40 amLHR - STL
2 stops21h 24mScandinavian Airlines
Deal found 8/17$708
This Gotogate deal was found by Cheapflights users on 8/16. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/214:05 pmSTL - LHR
1 stop11h 55mAir Canada
Tue 10/72:05 pmLHR - STL
1 stop11h 52mAir Canada
Deal found 8/16$709
This Scandinavian Airlines deal was found by Cheapflights users on 8/17. 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 Scandinavian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/143:59 pmSTL - LHR
2 stops18h 01mScandinavian Airlines
Wed 10/225:00 pmLHR - STL
2 stops36h 41mScandinavian Airlines
Deal found 8/17$720
This United Airlines deal was found by Cheapflights users on 8/18. 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 10/81:30 pmSTL - LHR
1 stop11h 00mUnited Airlines
Wed 10/156:30 amLHR - STL
1 stop13h 00mUnited Airlines
Deal found 8/18$724
This United Airlines deal was found by Cheapflights users on 8/15. 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.
Tue 10/141:30 pmSTL - LHR
1 stop14h 05mUnited Airlines
Wed 10/226:30 amLHR - STL
1 stop13h 00mUnited Airlines
Deal found 8/15$725
This United Airlines deal was found by Cheapflights users on 8/16. 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.
Wed 11/511:05 amSTL - LHR
1 stop14h 50mUnited Airlines
Tue 11/111:25 pmLHR - STL
2 stops31h 00mUnited Airlines
Deal found 8/16$728
This United Airlines deal was found by Cheapflights users on 8/17. 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.
Tue 11/114:55 pmSTL - LHR
1 stop34h 45mUnited Airlines
Tue 11/182:30 pmLHR - STL
2 stops37h 24mUnited Airlines
Deal found 8/17$729

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 August 18, 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

Fri 11/7

3:59 pm-4:00 pm

2 stops18h 01m

London Heathrow

Sun 11/9

6:40 am-11:39 pm

3 stops22h 59m

$635

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Thu 9/4

1:21 pm-9:40 pm

2 stops26h 19m

London Heathrow

Tue 9/16

6:40 am-10:00 pm

2 stops21h 20m

$674

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Thu 10/2

1:26 pm-5:40 pm

2 stops22h 14m

London Heathrow

Thu 10/9

6:40 am-11:41 pm

2 stops23h 01m

$699

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Sat 10/11

1:30 pm-5:40 pm

2 stops22h 10m

London Heathrow

Sat 10/25

6:40 am-10:04 pm

2 stops21h 24m

$708

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Sat 9/27

3:55 pm-5:40 pm

2 stops19h 45m

London Heathrow

Fri 10/3

6:40 am-9:15 pm

2 stops20h 35m

$708

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Fri 10/24

3:59 pm-1:35 pm

2 stops15h 36m

London Heathrow

Sat 11/1

6:40 am-10:04 pm

2 stops20h 24m

$708

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Thu 10/2

1:26 pm-4:00 pm

2 stops20h 34m

London Heathrow

Mon 10/6

6:40 am-11:41 pm

2 stops23h 01m

$708

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Sun 9/21

4:05 pm-10:00 am

1 stop11h 55m

London Heathrow

Tue 10/7

2:05 pm-7:57 pm

1 stop11h 52m

$709

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Mon 10/20

7:52 pm-10:00 pm

3 stops44h 08m

$278

St. LouisLondon

STL - LHR

STLLHR

Lambert-St Louis

Sat 10/18

7:52 pm-10:00 pm

3 stops44h 08m

$278

Flights are sorted by cheapest round-trip flights first.

Deals found on 8/17

Showing 1-10 of 17 results
1
2

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 August 8, 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 August 18, 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.

What’s the top layover airport for flights from St. Louis to London Heathrow Airport?

Share of 1-stop round-trip flights from St. Louis to London Heathrow Airport chosen by Cheapflights users in the past 12 months, using the same layover each way.

Chicago (ORD) – chosen by Cheapflights users on 57% of 1-stop itineraries from St. Louis to London Heathrow Airport on Cheapflights.

What’s the cheapest layover airport for flights from St. Louis to London Heathrow Airport?

Average round-trip fare for 1-stop flights from St. Louis to London Heathrow Airport, chosen by Cheapflights users in the past 12 months, with the same layover each way.

Frankfurt am Main (FRA) is the most affordable 1-stop option, with an average round-trip price of $797.

What’s the fastest layover option from St. Louis to London Heathrow Airport?

Shortest average travel time for 1-stop one-way flights from St. Louis to London Heathrow Airport, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by layover airport.

Flights via Chicago (ORD) have the shortest average one-way travel time for 1-stop routes: 10h 06m.

Which airport typically offers the quickest layover for flights from St. Louis to London Heathrow Airport?

Average layover duration for 1-stop one-way flights from St. Louis to London Heathrow Airport, chosen by Cheapflights users in the last 12 months, grouped by stopover airport.

Flights via Chicago (ORD) offer the fastest connection on this route, with an average layover time of 1h 31m.

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 August 18, 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
8,925 reviews

Crew

8.1

Boarding

7.7

Comfort

7.3

Food

6.6

Overall

7.4

Entertainment

7.1

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
8,925 reviews
United Airlines
7.4
Good
8,925 reviews

Crew

8.1

Boarding

7.7

Comfort

7.3

Food

6.6

Overall

7.4

Entertainment

7.1

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
8,925 reviews

Crew

8.1

Boarding

7.7

Comfort

7.3

Food

6.6

Overall

7.4

Entertainment

7.1

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
9,992 reviews
United Airlines
7.4
Good
8,925 reviews

Crew

8.1

Boarding

7.7

Comfort

7.3

Food

6.6

Overall

7.4

Entertainment

7.1

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
2,884 reviews
United Airlines
7.4
Good
8,925 reviews

Crew

8.1

Boarding

7.7

Comfort

7.3

Food

6.6

Overall

7.4

Entertainment

7.1

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
7,277 reviews
United Airlines
7.4
Good
8,925 reviews

Crew

8.1

Boarding

7.7

Comfort

7.3

Food

6.6

Overall

7.4

Entertainment

7.1

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?

    Scandinavian Airlines can get you from St. Louis to London Heathrow Airport in just under 18h 01m. Your travel time can differ by up to . Airlines will cover a distance of 4186 mi.

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

    According to our current data, KLM ($530), Delta ($631), and British Airways ($657) 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
Thornton Heath
Harrow
Canterbury
Dartford
Dover
Stratford-upon-Avon
Orpington
Watford
Northampton
Gatwick
Borehamwood
Broadway
Aylesbury
Chelmsford
Southend-on-Sea
Folkestone
Chichester
Swindon

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 August 18, 2025.
AirlineCheapestAverageFlexibilityOn-time
KLMCheapest$530Average$736FlexibilityNo cancel feeOn-time75%
DeltaCheapest$631Average$962FlexibilityNo cancel feeOn-timeN/A
British AirwaysCheapest$657Average$948FlexibilityNo cancel feeOn-time70%
Scandinavian AirlinesCheapest$669Average$1,102FlexibilityNo cancel feeOn-time77%
American AirlinesCheapest$671Average$965FlexibilityNo cancel feeOn-time71%
IberiaCheapest$673Average$976FlexibilityNo cancel feeOn-time77%
United AirlinesCheapest$685Average$927FlexibilityNo cancel feeOn-time69%
Air CanadaCheapest$691Average$960FlexibilityNo cancel feeOn-time67%
LufthansaCheapest$725Average$1,085FlexibilityNo cancel feeOn-time76%
Virgin AtlanticCheapest$727Average$913FlexibilityNo cancel feeOn-time72%

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