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

The Lambert-St Louis to Key Largo flight path was viewed by 58 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 $75. Users have also found prices from $112 and $124 on American Airlines and Delta, respectively.

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.

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).

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

On average you can expect to pay $711 for a flight from St. Louis to Key Largo. The cheapest flight overall is $144 while the most popular route, (Lambert-St Louis - Miami) is currently priced at $232.

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 GOL (71%), Qatar Airways (68%) and Royal Air Maroc (68%).

What are the most popular airlines that fly from St. Louis to Key Largo?

Consider American Airlines, Southwest or Frontier when booking your flight. These represent the most popular airlines when flying from St. Louis to Key Largo.

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 1 outbound flight to Key Largo per day. 6 airlines have flights to Key Largo from Lambert-St Louis on a regular basis.

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.

Find Cheap Flights from St. Louis to Key Largo

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Cheapflights Tip: The best prices from Lambert-St Louis to Key Largo are usually found in September or August, booked 84 days in advance, depart on a Monday or Saturday and return on a Thursday

Find flight deals from St. Louis to Key Largo

Most accurate provider	FlightHub 3 stars
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Popular in	June
Cheapest in	September
Average price	$367

Provider with most accurate pricing for Lambert-St Louis-Miami flight deals.

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Highest demand for flights based on searches. 6% potential increase in price ($28 potential increase over avg. RT price).

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Cheapest flight prices on average. 1% potential price decrease ($6 potential savings vs. average RT price).

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Average for round-trip flights in September 2026

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Everything you need to know about your flight from St. Louis to Key Largo

What is the cheapest time of day to fly from STL to KE9?

It’s optimal to fly from St. Louis to Key Largo in the evening. By choosing this option you can save up to 15% on the cost of your flight, compared to a flight in the morning.

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

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

Reviews of airlines servicing Key Largo

Peruse reviews from past customers who have flown with Southwest,Delta, andJetBlue from St. Louis to Key Largo to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.

Southwest

8.0

Very good

4,201 reviews

Reviews

1 / 20

6.0

Good

Scott,Feb 2026

HOU - FLL

Delayed by 45 minutes leaving Houston, making a 3.5 hour layover that much longer.

Southwest

8.0

Very good

4,201 reviews

Southwest

8.0

Very good

4,201 reviews

Reviews

1 / 20

6.0

Good

Scott,Feb 2026

HOU - FLL

Delayed by 45 minutes leaving Houston, making a 3.5 hour layover that much longer.

Delta

7.8

Good

8,611 reviews

Southwest

8.0

Very good

4,201 reviews

Reviews

1 / 20

6.0

Good

Scott,Feb 2026

HOU - FLL

Delayed by 45 minutes leaving Houston, making a 3.5 hour layover that much longer.

JetBlue

7.1

Good

3,041 reviews

Southwest

8.0

Very good

4,201 reviews

Reviews

1 / 20

6.0

Good

Scott,Feb 2026

HOU - FLL

Delayed by 45 minutes leaving Houston, making a 3.5 hour layover that much longer.

American Airlines

7.0

Good

12,095 reviews

Southwest

8.0

Very good

4,201 reviews

Reviews

1 / 20

6.0

Good

Scott,Feb 2026

HOU - FLL

Delayed by 45 minutes leaving Houston, making a 3.5 hour layover that much longer.

Frontier

5.6

Fair

2,568 reviews

Southwest

8.0

Very good

4,201 reviews

Reviews

1 / 20

6.0

Good

Scott,Feb 2026

HOU - FLL

Delayed by 45 minutes leaving Houston, making a 3.5 hour layover that much longer.

Related info for your journey

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 1 outbound flight 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 58 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 $75. Users have also found prices from $112 and $124 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 GOL (71%), Qatar Airways (68%) and Royal Air Maroc (68%).
What are the cheapest flights from St. Louis to Key Largo?
On average you can expect to pay $711 for a flight from St. Louis to Key Largo. The cheapest flight overall is $144 while the most popular route, (Lambert-St Louis - Miami) is currently priced at $232.
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.

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Top 6 airlines flying from St. Louis to Key Largo

Airline	Cheapest	Average	Flexibility	On-time
Frontier	Cheapest$127	Average$235	FlexibilityNo cancel fee	On-time62%
American Airlines	Cheapest$191	Average$435	FlexibilityNo cancel fee	On-time71%
JetBlue	Cheapest$220	Average$406	FlexibilityNo cancel fee	On-time62%
Delta	Cheapest$229	Average$446	FlexibilityNo cancel fee	On-timeN/A
United Airlines	Cheapest$232	Average$460	FlexibilityNo cancel fee	On-time69%
Southwest	Cheapest$288	Average$463	FlexibilityNo cancel fee	On-time63%

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

Find cheap flights from St. Louis to Key Largo with Cheapflights

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2. Select your favorite providers

3. Compare prices and book

Find flight deals from St. Louis to Key Largo

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Cheapflights Insights

What is the cheapest time of day to fly from STL to KE9?

It’s optimal to fly from St. Louis to Key Largo in the evening. By choosing this option you can save up to 15% on the cost of your flight, compared to a flight in the morning.

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

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

Reviews of airlines servicing Key Largo

Peruse reviews from past customers who have flown with Southwest,Delta, andJetBlue from St. Louis to Key Largo to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.

Related info for your journey

What airport do you fly from for flights from St. Louis to Key Largo?

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

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

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

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

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

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

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

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.

Alternative routes for St. Louis to Key Largo

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Complete your trip

Complete your trip to Key Largo by adding a car rental and/or hotel reservation to your travel itinerary.

Search flights from St. Louis to Key Largo by cabin class

Find flights from St. Louis to Key Largo, based on your preferred cabin class, be it economy, premium economy, business, or first class.

St. Louis and Key Largo flights

Browse other St. Louis and Key Largo flight options. Last updated on September 29, 2026.

Other flights from St. Louis

Browse through other flights departing from St. Louis. Flights are based on user searches made on Cheapflights and were last updated on September 29, 2026.

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Top 6 airlines flying from St. Louis to Key Largo

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