HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Keflavik Intl

$610+ Cheap flights from St. Louis (STL) to Keflavik Intl (KEF)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 11/12. Fares are subject to change and may not be available on all flights or dates of travel.
STL — KEF
Oct 17 — Oct 241
Fri 10/17
Fri 10/24
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from St. Louis to Keflavik Intl with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheap flight deals from St. Louis to Keflavik Intl

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Keflavik Intl (KEF). 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

$620
(KAYAK)

Popular in

June

Cheapest in

April

Average price

$912
From Lambert-St Louis to Reykjavik Keflavik Intl
Search Deals
Highest demand for flights based on searches. 9% potential increase in price ($95 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($23 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in September 2025
Search Deals

Find flight deals from St. Louis to Keflavik Intl

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

This KAYAK 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/123:50 pmSTL - KEF
2 stops16h 25mLufthansa
Tue 11/183:20 pmKEF - STL
1 stop28h 35mLufthansa
Deal found 9/15$610
This Kiwi.com 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/127:45 pmSTL - KEF
1 stop28h 20mMultiple Airlines
Tue 11/184:55 pmKEF - STL
1 stop22h 12mMultiple Airlines
Deal found 9/14$664
This Kiwi.com 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/117:45 pmSTL - KEF
1 stop28h 20mMultiple Airlines
Tue 11/184:55 pmKEF - STL
1 stop22h 12mMultiple Airlines
Deal found 9/14$682
This KAYAK 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/116:43 pmSTL - KEF
2 stops37h 32mLufthansa
Tue 11/183:20 pmKEF - STL
1 stop28h 35mLufthansa
Deal found 9/14$703
This FlightHub 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/131:55 pmSTL - KEF
2 stops28h 00mScandinavian Airlines
Wed 11/1911:30 amKEF - STL
2 stops39h 34mScandinavian Airlines
Deal found 9/15$738
This Finnair deal was found by Cheapflights users on 9/17. 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 Finnair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/51:20 pmSTL - KEF
2 stops37h 55mFinnair
Wed 11/1210:00 amKEF - STL
2 stops39h 30mFinnair
Deal found 9/17$754
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.
Fri 11/1411:05 amSTL - KEF
3 stops20h 15mMultiple Airlines
Tue 11/183:20 pmKEF - STL
2 stops29h 05mMultiple Airlines
Deal found 9/15$772

Cheapflights Fare Finder

 
Customize your flight search to find flights from St. Louis to Keflavik Intl 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 Reykjavik Keflavik Intl Airport that are best for you.

Fly from

St. Louis

Fly to

Keflavik Intl

Route

Depart

Return

Price

St. LouisReykjavik

STL - KEF

STLKEF

Lambert-St Louis

Wed 11/12

3:50 pm-2:15 pm

2 stops16h 25m

Reykjavik Keflavik Intl

Tue 11/18

3:20 pm-1:55 pm

1 stop28h 35m

$610

St. LouisReykjavik

STL - KEF

STLKEF

Lambert-St Louis

Fri 11/14

11:42 am-5:15 pm

2 stops23h 33m

Reykjavik Keflavik Intl

Tue 11/18

10:00 am-7:30 pm

2 stops39h 30m

$754

St. LouisReykjavik

STL - KEF

STLKEF

Lambert-St Louis

Tue 11/11

6:43 pm-2:15 pm

2 stops37h 32m

Reykjavik Keflavik Intl

Tue 11/18

3:20 pm-1:55 pm

1 stop28h 35m

$771

St. LouisReykjavik

STL - KEF

STLKEF

Lambert-St Louis

Fri 11/14

11:05 am-1:20 pm

3 stops20h 15m

Reykjavik Keflavik Intl

Tue 11/18

3:20 pm-2:25 pm

2 stops29h 05m

$772

St. LouisReykjavik

STL - KEF

STLKEF

Lambert-St Louis

Wed 10/1

4:10 pm-9:30 am

1 stop12h 20m

Reykjavik Keflavik Intl

Wed 10/8

8:45 am-5:29 pm

1 stop13h 44m

$798

St. LouisReykjavik

STL - KEF

STLKEF

Lambert-St Louis

Wed 10/1

6:40 am-9:30 am

2 stops21h 50m

Reykjavik Keflavik Intl

Wed 10/8

8:45 am-1:22 pm

1 stop9h 37m

$888

St. LouisReykjavik

STL - KEF

STLKEF

Lambert-St Louis

Thu 10/16

12:25 pm-11:35 pm

2 stops30h 10m

Reykjavik Keflavik Intl

Wed 10/22

12:25 am-3:44 pm

2 stops20h 19m

$893

St. LouisReykjavik

STL - KEF

STLKEF

Lambert-St Louis

Fri 10/3

4:05 pm-8:15 am

1 stop11h 10m

Reykjavik Keflavik Intl

Tue 10/7

9:50 am-10:49 am

2 stops29h 59m

$894

St. LouisReykjavik

STL - KEF

STLKEF

Lambert-St Louis

Fri 9/26

9:10 am-8:40 am

1 stop18h 30m

$1,889

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/17

Best time to book a flight from St. Louis to Keflavik Intl

Have a flexible travel schedule? Discover the best time to fly to Keflavik Intl 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 Reykjavik Keflavik Intl Airport

What is the cheapest month to book a flight from St. Louis to Reykjavik Keflavik Intl Airport?

Currently, November is the cheapest month in which you can book a flight from St. Louis to Reykjavik Keflavik Intl Airport (average of $328). Flying from St. Louis to Reykjavik Keflavik Intl Airport in June is currently the most expensive (average of $656). 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.

Reviews of airlines servicing Keflavik Intl

Get insights into the airlines that provide service to Keflavik Intl. 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 Keflavik Intl. Reviews last updated September 17, 2025.
See what other customers who have flown with Delta, KLM, and United Airlines from St. Louis to Reykjavik Keflavik Intl Airport have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very good
7,961 reviews

Entertainment

7.9

Comfort

7.9

Overall

8.0

Crew

8.5

Boarding

8.2

Food

7.3

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
Delta
8.0
Very good
7,961 reviews
Delta
8.0
Very good
7,961 reviews

Entertainment

7.9

Comfort

7.9

Overall

8.0

Crew

8.5

Boarding

8.2

Food

7.3

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
KLM
7.8
Good
1,386 reviews
Delta
8.0
Very good
7,961 reviews

Entertainment

7.9

Comfort

7.9

Overall

8.0

Crew

8.5

Boarding

8.2

Food

7.3

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
United Airlines
7.4
Good
8,926 reviews
Delta
8.0
Very good
7,961 reviews

Entertainment

7.9

Comfort

7.9

Overall

8.0

Crew

8.5

Boarding

8.2

Food

7.3

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
Air Canada
7.1
Good
10,000 reviews
Delta
8.0
Very good
7,961 reviews

Entertainment

7.9

Comfort

7.9

Overall

8.0

Crew

8.5

Boarding

8.2

Food

7.3

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Keflavik Intl. 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 Reykjavik Keflavik Intl?

    Located just 12.7 mi from the city center, Lambert-St Louis is the airport most travelers will use when flying to Reykjavik Keflavik Intl from St. Louis. Booking flights from Lambert-St Louis (STL) to Reykjavik Keflavik Intl should be relatively easy as there are 0 daily outbound flights to Reykjavik Keflavik Intl from 4 different airlines.

  • How long is the flight from St. Louis to Reykjavik Keflavik Intl Airport?

    Departing from St. Louis to Reykjavik Keflavik Intl Airport will take you 16h 25m. The distance from St. Louis to Reykjavik Keflavik Intl Airport is about 3191 mi.

  • What are the cheapest airlines flying from St. Louis to Reykjavik Keflavik Intl Airport round-trip?

    Our cheapest airline available from St. Louis to Reykjavik Keflavik Intl Airport is Air Canada. Our recent data shows that you can find tickets from as low as $566 on this airline. Additional options worth looking into are United Airlines and Delta, starting at $595 and $636 round-trip. Air Canada is 41% 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 Keflavik Intl that include hotel bookings?

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

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

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

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

    Yes. Cheapflights offers flight deals from St. Louis to Keflavik Intl 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 Reykjavik Keflavik Intl Airport?

    Currently, November is the cheapest month in which you can book a flight from St. Louis to Reykjavik Keflavik Intl Airport (average of $328). Flying from St. Louis to Reykjavik Keflavik Intl Airport in June is currently the most expensive (average of $656). 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 Reykjavik Keflavik Intl Airport?

Book flights to Reykjavik Keflavik Intl Airport if you plan to visit one of these locations
Keflavik
Hveragerdi

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 4 airlines flying from St. Louis to Keflavik Intl

Discover the top 4 airlines that operate flights from St. Louis to Keflavik Intl. 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
Air CanadaCheapest$566Average$672FlexibilityNo cancel feeOn-time67%
United AirlinesCheapest$595Average$1,115FlexibilityNo cancel feeOn-time69%
DeltaCheapest$636Average$1,112FlexibilityNo cancel feeOn-timeN/A
KLMCheapest$828Average$1,147FlexibilityNo cancel feeOn-time75%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.