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Key Largo

$98+ Cheap flights from St. Louis (STL) to Key Largo, FL

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 5/21. Fares are subject to change and may not be available on all flights or dates of travel.
STL — MIA
May 5 — May 121
Mon 5/5
Mon 5/12
1 adult, Economy
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Cheapflights Tip: The best prices from Lambert-St Louis to Key Largo are usually found in August or September, booked 72 days in advance, depart on a Friday or Sunday and return on a Thursday

Cheap flight deals from St. Louis to Key Largo

Keep the following information in mind while searching for St. Louis to Key Largo flight deals. Data was last updated April 30, 2025.

Most accurate provider

Mytrip
3 stars

Most trusted provider

Mytrip
3 stars

Round-trip from

$219
(Delta)

One-way from

$98
(Cheapflightsfares)

Popular in

March

Cheapest in

August

Average price

$399
Provider with most accurate pricing for Lambert-St Louis-Miami flight deals.
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Provider most trusted by Cheapflights users for Lambert-St Louis-Miami flights.
Search Deals
From Lambert-St Louis to Key Largo
Search Deals
One-way flight from Lambert-St Louis to Key Largo
Search Deals
Highest demand for flights based on searches. 10% potential increase in price ($48 potential increase over avg. RT price).
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Cheapest flight prices on average. 3% potential price decrease ($12 potential savings vs. average RT price).
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Average for round-trip flights in April 2025
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Find flight deals from St. Louis to Key Largo

Cheapest flights from St. Louis to Key Largo
Explore the most affordable flight options available from St. Louis to Key Largo. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 30, 2025.

This Delta deal was found by Cheapflights users on 4/29. 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 5/207:05 amSTL - MIA
1 stop5h 10mDelta
Wed 5/217:00 amMIA - STL
1 stop6h 04mDelta
Deal found 4/29$219
This American Airlines deal was found by Cheapflights users on 4/29. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/146:20 pmSTL - MIA
Nonstop2h 48mAmerican Airlines
Tue 5/203:30 pmMIA - STL
Nonstop2h 59mAmerican Airlines
Deal found 4/29$224
This CheapOair deal was found by Cheapflights users on 4/29. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/96:53 pmSTL - MIA
1 stop9h 29mFrontier
Sun 5/186:00 amMIA - STL
1 stop28h 09mFrontier
Deal found 4/29$228
This Priceline deal was found by Cheapflights users on 4/28. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 6/67:24 pmSTL - MIA
1 stop10h 06mMultiple Airlines
Mon 6/1610:11 amMIA - STL
1 stop9h 07mMultiple Airlines
Deal found 4/28$247
This Southwest deal was found by Cheapflights users on 4/29. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/198:10 amSTL - MIA
Nonstop2h 40mSouthwest
Wed 5/217:55 amMIA - STL
Nonstop2h 55mSouthwest
Deal found 4/29$264
This Mytrip deal was found by Cheapflights users on 4/29. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 6/126:12 pmSTL - MIA
1 stop13h 54mSpirit Airlines
Thu 6/1910:11 amMIA - STL
1 stop7h 53mSpirit Airlines
Deal found 4/29$276
This United Airlines deal was found by Cheapflights users on 4/28. 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.
Sat 9/136:15 amSTL - MIA
1 stop8h 31mUnited Airlines
Sat 9/204:53 pmMIA - STL
1 stop6h 15mUnited Airlines
Deal found 4/28$349

Cheapflights Fare Finder

Customize your flight search to find flights from St. Louis to Key Largo 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 April 30, 2025.
Use the filters below to find and compare flights from St. Louis to Key Largo that are best for you.

Fly from

St. Louis

Fly to

Key Largo

Route

Depart

Return

Price

St. LouisMiami

STL - MIA

STLMIA

Lambert-St Louis

Tue 5/20

7:05 am-1:15 pm

1 stop5h 10m

Miami

Wed 5/21

7:00 am-12:04 pm

1 stop6h 04m

$219

St. LouisMiami

STL - MIA

STLMIA

Lambert-St Louis

Wed 5/14

6:20 pm-10:08 pm

Nonstop2h 48m

Miami

Tue 5/20

3:30 pm-5:29 pm

Nonstop2h 59m

$224

St. LouisMiami

STL - MIA

STLMIA

Lambert-St Louis

Fri 5/9

6:53 pm-5:22 am

1 stop9h 29m

Miami

Sun 5/18

6:00 am-9:09 am

1 stop28h 09m

$228

St. LouisMiami

STL - MIA

STLMIA

Lambert-St Louis

Fri 6/6

7:24 pm-6:30 am

1 stop10h 06m

Miami

Mon 6/16

10:11 am-6:18 pm

1 stop9h 07m

$247

St. LouisMiami

STL - MIA

STLMIA

Lambert-St Louis

Mon 5/19

8:10 am-11:50 am

Nonstop2h 40m

Miami

Wed 5/21

7:55 am-9:50 am

Nonstop2h 55m

$264

St. LouisMiami

STL - MIA

STLMIA

Lambert-St Louis

Thu 6/12

6:12 pm-9:06 am

1 stop13h 54m

Miami

Thu 6/19

10:11 am-5:04 pm

1 stop7h 53m

$276

St. LouisMiami

STL - MIA

STLMIA

Lambert-St Louis

Tue 5/20

9:40 am-10:29 pm

2 stops11h 49m

Miami

Wed 5/21

9:00 am-3:49 pm

1 stop7h 49m

$410

St. LouisMiami

STL - MIA

STLMIA

Lambert-St Louis

Wed 5/21

8:15 pm-5:22 am

1 stop8h 07m

$98

St. LouisMiami

STL - MIA

STLMIA

Lambert-St Louis

Wed 5/21

6:20 pm-10:08 pm

Nonstop2h 48m

$100

St. LouisMiami

STL - MIA

STLMIA

Lambert-St Louis

Tue 5/20

10:05 am-4:51 pm

1 stop5h 46m

$110

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/29

Showing 1-10 of 15 results
1
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Best time to book a flight from St. Louis to Key Largo

Have a flexible travel schedule? Discover the best time to fly to Key Largo 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 Key Largo

How far ahead should I book a flight from St. Louis to Key Largo?

Use this chart to determine the optimal time to book a round-trip flight from St. Louis to Key Largo. Price data was last updated on April 25, 2025.

To ensure you get the cheapest price possible for a flight from St. Louis to Key Largo, you should look to book at least 72 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 Key Largo?

Currently, September is the cheapest month in which you can book a flight from St. Louis to Key Largo (average of $228). Flying from St. Louis to Key Largo in March is currently the most expensive (average of $289). 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 KE9?

Find hourly flight availability from St. Louis to Key Largo. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated April 30, 2025.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from St. Louis to Key Largo as you normally would.

What is the cheapest day to fly from St. Louis to Key Largo?

Use this chart to determine the cheapest time to fly round-trip from St. Louis to Key Largo. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their St. Louis to Key Largo flight should consider departing on Monday evenings when fares are most often at their lowest. Tuesday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from St. Louis to Key Largo

Explore weekly flight availability from St. Louis to Key Largo. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated April 30, 2025.

The most flights from STL to KE9 are scheduled on a Tuesday (6 on average). You will have fewer flight options on Friday, which is when the least amount of flights are scheduled (3 on average).

Rainfall in Key Largo by month

Plan your trip to Key Largo by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Key Largo ranges from 1.6 - 9.9 inches per month. September is typically the wettest month, when rainfall can reach 9.9 in. January is typically the driest time to visit Key Largo when rainfall is around 1.6 in.

Temperature in Key Largo by month

Plan your trip to Key Largo by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Key Largo, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 84.2 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 68.0 F).

Reviews of airlines servicing Key Largo

Get insights into the airlines that provide service to Key Largo. 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 Key Largo. Reviews last updated April 30, 2025.
Peruse reviews from past customers who have flown with Alaska Airlines, Southwest and Delta from St. Louis to Key Largo to help guide your decision. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
9,961 reviews

Entertainment

7.1

Boarding

8.2

Comfort

7.9

Food

7.1

Crew

8.5

Overall

8.0

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Alaska Airlines
8.0
Very good
9,961 reviews
Alaska Airlines
8.0
Very good
9,961 reviews

Entertainment

7.1

Boarding

8.2

Comfort

7.9

Food

7.1

Crew

8.5

Overall

8.0

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Southwest
8.0
Very good
4,295 reviews
Alaska Airlines
8.0
Very good
9,961 reviews

Entertainment

7.1

Boarding

8.2

Comfort

7.9

Food

7.1

Crew

8.5

Overall

8.0

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Delta
8.0
Very good
7,936 reviews
Alaska Airlines
8.0
Very good
9,961 reviews

Entertainment

7.1

Boarding

8.2

Comfort

7.9

Food

7.1

Crew

8.5

Overall

8.0

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
United Airlines
7.4
Good
8,696 reviews
Alaska Airlines
8.0
Very good
9,961 reviews

Entertainment

7.1

Boarding

8.2

Comfort

7.9

Food

7.1

Crew

8.5

Overall

8.0

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
American Airlines
7.2
Good
10,000 reviews
Alaska Airlines
8.0
Very good
9,961 reviews

Entertainment

7.1

Boarding

8.2

Comfort

7.9

Food

7.1

Crew

8.5

Overall

8.0

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Key Largo. 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 Key Largo?

    For a flight from St. Louis to Key Largo, you will be flying from Lambert-St Louis. Lambert-St Louis (STL) is just 12.7 mi from the center of the city. Lambert-St Louis is the only St. Louis airport and it handles 4 outbound flights to Key Largo per day. 6 airlines have flights to Key Largo from Lambert-St Louis on a regular basis.

  • How popular is this St. Louis to Key Largo flight route?

    The Lambert-St Louis to Key Largo flight path was viewed by 23 users in the past month. Keep an eye out for changes in search interest prior to high and low season.

  • What are the cheapest airlines to fly from St. Louis to Key Largo one-way?

    For one-way options, check prices for Frontier. According to our data, you can fly for as low as $98. Users have also found prices from $100 and $110 on American Airlines and Delta, respectively.

  • What are the most reliable airlines from St. Louis to Key Largo?

    The top 3 most reliable airlines when flying from St. Louis to Key Largo are American Airlines (79%), Qatar Airways (78%) and Envoy Air (76%).

  • What are the cheapest flights from St. Louis to Key Largo?

    On average you can expect to pay $412 for a flight from St. Louis to Key Largo. The cheapest flight overall is $89 while the most popular route, (Lambert-St Louis - Miami) is currently priced at $221.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from St. Louis to Key Largo 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 Key Largo?

    Currently, September is the cheapest month in which you can book a flight from St. Louis to Key Largo (average of $228). Flying from St. Louis to Key Largo in March is currently the most expensive (average of $289). 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.

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Top 6 airlines flying from St. Louis to Key Largo

Discover the top 6 airlines that operate flights from St. Louis to Key Largo. 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 April 30, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$68Average$141FlexibilityNo cancel feeOn-time65%
FrontierCheapest$130Average$231FlexibilityNo cancel feeOn-time62%
DeltaCheapest$208Average$422FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$219Average$420FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$268Average$478FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$292Average$466FlexibilityNo cancel feeOn-time63%

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