$59+ 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 3/2. Fares are subject to change and may not be available on all flights or dates of travel.
STL — MIA
Mar 5 — Mar 121
1 adult, Economy
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Find cheap flights from St. Louis to Key Largo 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.Cheapflights Tip: The best prices from Lambert-St Louis to Key Largo are usually found in September or October, booked 33 days in advance, depart on a Sunday or Wednesday and return on a Thursday
Cheap flight deals from St. Louis to Key Largo
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Best
Last-minute
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Cheapest flights from St. Louis to Key LargoExplore 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 February 3, 2026.
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 February 3, 2026.
This Kiwi.com deal was found by Cheapflights users on 2/1. 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.
Sat 2/212:51 pm
STL
- MIA
1 stop13h 23m
Multiple Airlines
Mon 2/237:05 am
MIA
- STL
2 stops13h 57m
Multiple Airlines
Deal found 2/1![Multiple Airlines logo]()
$290
This Kiwi.com deal was found by Cheapflights users on 2/2. 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.
Fri 3/1312:16 pm
STL
- MIA
1 stop11h 31m
Frontier
Mon 3/167:04 pm
MIA
- STL
2 stops29h 15m
Frontier
Deal found 2/2![Frontier logo]()
$291
This Kiwi.com deal was found by Cheapflights users on 2/1. 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.
Fri 2/208:20 pm
STL
- MIA
1 stop13h 08m
Frontier
Sun 2/227:09 pm
MIA
- STL
1 stop12h 42m
Frontier
Deal found 2/1![Frontier logo]()
$292
This Kiwi.com deal was found by Cheapflights users on 2/1. 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 2/103:49 pm
STL
- MIA
2 stops28h 19m
Frontier
Fri 2/137:09 pm
MIA
- STL
1 stop12h 42m
Frontier
Deal found 2/1![Frontier logo]()
$293
This Kiwi.com deal was found by Cheapflights users on 2/2. 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.
Sat 2/711:00 am
STL
- MIA
2 stops12h 47m
Frontier
Sun 2/155:05 am
MIA
- STL
1 stop26h 46m
Frontier
Deal found 2/2![Frontier logo]()
$294
This Southwest deal was found by Cheapflights users on 2/1. 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 4/131:50 pm
STL
- MIA
Nonstop2h 40m
Southwest
Sat 4/186:15 am
MIA
- STL
1 stop4h 35m
Southwest
Deal found 2/1![Southwest logo]()
$295
This American Airlines deal was found by Cheapflights users on 2/2. 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 3/45:14 am
STL
- MIA
Nonstop2h 55m
American Airlines
Wed 3/118:20 am
MIA
- STL
Nonstop3h 12m
American Airlines
Deal found 2/2![American Airlines logo]()
$296
This Kiwi.com deal was found by Cheapflights users on 2/1. 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.
Fri 3/1312:16 pm
STL
- MIA
1 stop6h 51m
Multiple Airlines
Sun 3/157:00 am
MIA
- STL
2 stops31h 34m
Multiple Airlines
Deal found 2/1![Multiple Airlines logo]()
$297
This Kiwi.com deal was found by Cheapflights users on 2/2. 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.
Thu 2/2610:11 pm
STL
- MIA
2 stops25h 31m
Frontier
Sun 3/17:09 pm
MIA
- STL
1 stop12h 42m
Frontier
Deal found 2/2![Frontier logo]()
$298
This American Airlines deal was found by Cheapflights users on 2/2. 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 4/2212:25 pm
STL
- MIA
1 stop5h 59m
American Airlines
Mon 4/278:15 am
MIA
- STL
Nonstop3h 01m
American Airlines
Deal found 2/2![American Airlines logo]()
$299
This Kiwi.com deal was found by Cheapflights users on 2/2. 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.
Sat 2/711:00 am
STL
- MIA
2 stops12h 47m
Frontier
Sun 2/812:11 pm
MIA
- STL
1 stop19h 40m
Frontier
Deal found 2/2![Frontier logo]()
$300
This Kiwi.com deal was found by Cheapflights users on 2/1. 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.
Sun 3/158:06 pm
STL
- MIA
2 stops37h 11m
Multiple Airlines
Fri 3/205:05 am
MIA
- STL
1 stop9h 29m
Multiple Airlines
Deal found 2/1![Multiple Airlines logo]()
$301
Best flights from St. Louis to Key LargoDiscover carefully curated flight deals from St. Louis to Key Largo that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated February 3, 2026.
Discover carefully curated flight deals from St. Louis to Key Largo that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated February 3, 2026.
This American Airlines deal was found by Cheapflights users on 2/2. 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 3/45:14 am
STL
- MIA
Nonstop2h 55m
American Airlines
Wed 3/118:20 am
MIA
- STL
Nonstop3h 12m
American Airlines
Deal found 2/2![American Airlines logo]()
$296
This Southwest deal was found by Cheapflights users on 2/2. 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.
Wed 5/62:10 pm
STL
- MIA
2 stops6h 45m
Southwest
Tue 5/126:15 am
MIA
- STL
2 stops7h 35m
Southwest
Deal found 2/2![Southwest logo]()
$309
This Delta deal was found by Cheapflights users on 1/31. 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 3/86:59 pm
STL
- MIA
1 stop4h 53m
Delta
Wed 3/117:05 am
MIA
- STL
1 stop5h 04m
Delta
Deal found 1/31![Delta logo]()
$323
This United Airlines deal was found by Cheapflights users on 2/1. 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.
Thu 4/237:45 am
STL
- MIA
2 stops9h 43m
United Airlines
Wed 4/291:20 pm
MIA
- STL
2 stops8h 48m
United Airlines
Deal found 2/1![United Airlines logo]()
$333
This Delta deal was found by Cheapflights users on 2/1. 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 3/86:59 pm
STL
- MIA
1 stop4h 53m
Delta
Fri 3/137:05 am
MIA
- STL
1 stop5h 04m
Delta
Deal found 2/1![Delta logo]()
$323
This Southwest deal was found by Cheapflights users on 2/1. 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.
Sun 6/73:55 pm
STL
- MIA
Nonstop2h 45m
Southwest
Sat 6/138:45 pm
MIA
- STL
1 stop12h 45m
Southwest
Deal found 2/1![Southwest logo]()
$371
This United Airlines deal was found by Cheapflights users on 2/2. 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.
Thu 3/127:41 am
STL
- MIA
1 stop8h 47m
United Airlines
Wed 3/254:10 pm
MIA
- STL
1 stop6h 32m
United Airlines
Deal found 2/2![United Airlines logo]()
$375
This Southwest deal was found by Cheapflights users on 2/1. 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.
Sun 8/23:55 pm
STL
- MIA
Nonstop2h 45m
Southwest
Sat 8/87:45 am
MIA
- STL
Nonstop2h 45m
Southwest
Deal found 2/1![Southwest logo]()
$376
This Southwest deal was found by Cheapflights users on 2/2. 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.
Wed 3/46:05 am
STL
- MIA
2 stops9h 05m
Southwest
Sun 3/86:00 am
MIA
- STL
1 stop7h 40m
Southwest
Deal found 2/2![Southwest logo]()
$379
This Southwest deal was found by Cheapflights users on 2/2. 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.
Tue 5/1911:35 am
STL
- MIA
2 stops9h 20m
Southwest
Fri 5/226:20 am
MIA
- STL
2 stops7h 30m
Southwest
Deal found 2/2![Southwest logo]()
$380
This Southwest deal was found by Cheapflights users on 2/2. 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.
Tue 5/1911:35 am
STL
- MIA
2 stops9h 20m
Southwest
Sat 5/236:35 am
MIA
- STL
2 stops8h 00m
Southwest
Deal found 2/2![Southwest logo]()
$380
This Southwest deal was found by Cheapflights users on 2/1. 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.
Fri 5/81:45 pm
STL
- MIA
2 stops6h 40m
Southwest
Sun 5/107:00 am
MIA
- STL
1 stop6h 50m
Southwest
Deal found 2/1![Southwest logo]()
$386
Last-minute flights from St. Louis to Key LargoDiscover last-minute flight deals from St. Louis to Key Largo. Data last updated February 3, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Key Largo. Data last updated February 3, 2026 and is based on user searches.
This Kiwi.com deal was found by Cheapflights users on 2/2. 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.
Sat 2/711:00 am
STL
- MIA
2 stops12h 47m
Frontier
Sun 2/155:05 am
MIA
- STL
1 stop26h 46m
Frontier
Deal found 2/2![Frontier logo]()
$294
This Kiwi.com deal was found by Cheapflights users on 2/2. 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.
Sat 2/711:00 am
STL
- MIA
2 stops12h 47m
Frontier
Sun 2/812:11 pm
MIA
- STL
1 stop19h 40m
Frontier
Deal found 2/2![Frontier logo]()
$300
This Kiwi.com deal was found by Cheapflights users on 2/1. 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 2/103:49 pm
STL
- MIA
2 stops28h 19m
Frontier
Fri 2/137:09 pm
MIA
- STL
1 stop12h 42m
Frontier
Deal found 2/1![Frontier logo]()
$293
This Kiwi.com deal was found by Cheapflights users on 2/1. 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.
Fri 2/208:20 pm
STL
- MIA
1 stop13h 08m
Frontier
Sun 2/227:09 pm
MIA
- STL
1 stop12h 42m
Frontier
Deal found 2/1![Frontier logo]()
$292
This Kiwi.com deal was found by Cheapflights users on 1/31. 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.
Fri 2/208:20 pm
STL
- MIA
1 stop14h 56m
Multiple Airlines
Sun 2/229:53 pm
MIA
- STL
2 stops16h 16m
Multiple Airlines
Deal found 1/31![Multiple Airlines logo]()
$299
This Kiwi.com deal was found by Cheapflights users on 2/1. 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.
Sat 2/212:51 pm
STL
- MIA
1 stop13h 23m
Multiple Airlines
Mon 2/237:05 am
MIA
- STL
2 stops13h 57m
Multiple Airlines
Deal found 2/1![Multiple Airlines logo]()
$290
This Kiwi.com deal was found by Cheapflights users on 2/2. 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.
Thu 2/2610:11 pm
STL
- MIA
2 stops25h 31m
Frontier
Sun 3/17:09 pm
MIA
- STL
1 stop12h 42m
Frontier
Deal found 2/2![Frontier logo]()
$298
This American Airlines deal was found by Cheapflights users on 2/2. 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 3/45:14 am
STL
- MIA
Nonstop2h 55m
American Airlines
Wed 3/118:20 am
MIA
- STL
Nonstop3h 12m
American Airlines
Deal found 2/2![American Airlines logo]()
$296
This Kiwi.com deal was found by Cheapflights users on 2/2. 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.
Fri 3/1312:16 pm
STL
- MIA
1 stop11h 31m
Frontier
Mon 3/167:04 pm
MIA
- STL
2 stops29h 15m
Frontier
Deal found 2/2![Frontier logo]()
$291
This Kiwi.com deal was found by Cheapflights users on 2/1. 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.
Fri 3/1312:16 pm
STL
- MIA
1 stop6h 51m
Multiple Airlines
Sun 3/157:00 am
MIA
- STL
2 stops31h 34m
Multiple Airlines
Deal found 2/1![Multiple Airlines logo]()
$297
This Kiwi.com deal was found by Cheapflights users on 2/1. 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.
Sun 3/158:06 pm
STL
- MIA
2 stops37h 11m
Multiple Airlines
Fri 3/205:05 am
MIA
- STL
1 stop9h 29m
Multiple Airlines
Deal found 2/1![Multiple Airlines logo]()
$301
This Kiwi.com deal was found by Cheapflights users on 2/1. 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 3/1811:32 am
STL
- MIA
1 stop12h 15m
Frontier
Sun 3/225:01 am
MIA
- STL
2 stops27h 01m
Frontier
Deal found 2/1![Frontier logo]()
$302
One-way flights from St. Louis to Key LargoSearch for one-way flight options from St. Louis to Key Largo. Find affordable one-way fares based on user searches. Data last updated February 3, 2026.
Search for one-way flight options from St. Louis to Key Largo. Find affordable one-way fares based on user searches. Data last updated February 3, 2026.
This Trip.com deal was found by Cheapflights users on 2/2. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/28:22 pm
STL
- MIA
1 stop13h 06m
Frontier
Deal found 2/2![Frontier logo]()
$59
This Trip.com deal was found by Cheapflights users on 2/1. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/258:17 pm
STL
- MIA
1 stop13h 11m
Frontier
Deal found 2/1![Frontier logo]()
$60
This Kiwi.com deal was found by Cheapflights users on 2/1. 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.
Mon 3/28:22 pm
STL
- MIA
1 stop14h 54m
Multiple Airlines
Deal found 2/1![Multiple Airlines logo]()
$63
This Trip.com deal was found by Cheapflights users on 2/2. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 2/168:22 pm
STL
- MIA
1 stop13h 06m
Frontier
Deal found 2/2![Frontier logo]()
$66
This Kiwi.com deal was found by Cheapflights users on 2/3. 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 3/3111:27 am
STL
- MIA
1 stop5h 26m
Frontier
Deal found 2/3![Frontier logo]()
$67
This Kiwi.com deal was found by Cheapflights users on 2/2. 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.
Sat 2/288:17 pm
STL
- MIA
1 stop27h 25m
Frontier
Deal found 2/2![Frontier logo]()
$68
This Kiwi.com deal was found by Cheapflights users on 2/1. 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 3/48:17 pm
STL
- MIA
1 stop14h 59m
Multiple Airlines
Deal found 2/1![Multiple Airlines logo]()
$69
This Trip.com deal was found by Cheapflights users on 2/3. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 2/278:22 pm
STL
- MIA
1 stop27h 20m
Frontier
Deal found 2/3![Frontier logo]()
$72
This Trip.com deal was found by Cheapflights users on 2/1. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 2/98:22 pm
STL
- MIA
1 stop19h 24m
Frontier
Deal found 2/1![Frontier logo]()
$75
This Kiwi.com deal was found by Cheapflights users on 2/1. 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 4/228:13 pm
STL
- MIA
1 stop13h 04m
Frontier
Deal found 2/1![Frontier logo]()
$76
Find 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 February 3, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $290 (Kiwi.com) |
One-way from | $59 (Trip.com) |
Popular in | March |
Cheapest in | September |
Average price | $409 |
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 February 3, 2026.
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
Wed 3/4
5:14 am-9:09 am
Nonstop2h 55m
Miami
Wed 3/11
8:20 am-10:32 am
Nonstop3h 12m
$296
St. LouisMiami
STL - MIA
STLMIA
Lambert-St Louis
Wed 5/6
2:10 pm-9:55 pm
2 stops6h 45m
Miami
Tue 5/12
6:15 am-12:50 pm
2 stops7h 35m
$309
St. LouisMiami
STL - MIA
STLMIA
Lambert-St Louis
Sun 3/8
6:59 pm-12:52 am
1 stop4h 53m
Miami
Wed 3/11
7:05 am-11:09 am
1 stop5h 04m
$323
St. LouisMiami
STL - MIA
STLMIA
Lambert-St Louis
Sun 3/8
6:59 pm-12:52 am
1 stop4h 53m
Miami
Fri 3/13
7:05 am-11:09 am
1 stop5h 04m
$323
St. LouisMiami
STL - MIA
STLMIA
Lambert-St Louis
Thu 4/23
7:45 am-6:28 pm
2 stops9h 43m
Miami
Wed 4/29
1:20 pm-9:08 pm
2 stops8h 48m
$333
St. LouisMiami
STL - MIA
STLMIA
Lambert-St Louis
Sun 6/7
3:55 pm-7:40 pm
Nonstop2h 45m
Miami
Sat 6/13
8:45 pm-8:30 am
1 stop12h 45m
$371
St. LouisMiami
STL - MIA
STLMIA
Lambert-St Louis
Thu 3/12
7:41 am-5:28 pm
1 stop8h 47m
Miami
Wed 3/25
4:10 pm-9:42 pm
1 stop6h 32m
$375
St. LouisMiami
STL - MIA
STLMIA
Lambert-St Louis
Sun 8/2
3:55 pm-7:40 pm
Nonstop2h 45m
Miami
Sat 8/8
7:45 am-9:30 am
Nonstop2h 45m
$376
St. LouisMiami
STL - MIA
STLMIA
Lambert-St Louis
Wed 3/4
6:05 am-4:10 pm
2 stops9h 05m
Miami
Sun 3/8
6:00 am-12:40 pm
1 stop7h 40m
$379
St. LouisMiami
STL - MIA
STLMIA
Lambert-St Louis
Tue 5/19
11:35 am-9:55 pm
2 stops9h 20m
Miami
Fri 5/22
6:20 am-12:50 pm
2 stops7h 30m
$380
Showing 1-10 of 23 results
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.
STL-MIA
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
STL-KE9
STL-MIA
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 January 30, 2026.
To ensure you get the cheapest price possible for a flight from St. Louis to Key Largo, you should look to book at least 33 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, February is the cheapest month in which you can book a flight from St. Louis to Key Largo (average of $68). Flying from St. Louis to Key Largo in June is currently the most expensive (average of $128). 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 February 3, 2026.
It’s optimal to fly from St. Louis to Key Largo in the afternoon. By choosing this option you can save up to 19% on the cost of your flight, compared to a flight at noon.
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 January 31, 2026.
Travelers seeking maximum savings on their St. Louis to Key Largo flight should consider departing on Tuesday afternoons when fares are most often at their lowest. Monday at noon 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 February 3, 2026.
The most flights from STL to KE9 are scheduled on a Saturday (11 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (4 on average).
How much does it cost to fly round-trip from St. Louis to Key Largo?
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 February 3, 2026.
Peruse reviews from past customers who have flown with Southwest, Delta, and American Airlines 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.
Food
7.0
Overall
8.0
Comfort
8.0
Boarding
8.1
Crew
8.6
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Overall
8.0
Comfort
8.0
Boarding
8.1
Crew
8.6
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Overall
8.0
Comfort
8.0
Boarding
8.1
Crew
8.6
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Overall
8.0
Comfort
8.0
Boarding
8.1
Crew
8.6
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Overall
8.0
Comfort
8.0
Boarding
8.1
Crew
8.6
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Overall
8.0
Comfort
8.0
Boarding
8.1
Crew
8.6
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
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.
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Alternative routes for St. Louis to Key Largo
See prices for flight routes from nearby airports that may be better suited for you.
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 February 3, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$68 | Average$155 | FlexibilityNo cancel fee | On-time65% | |
| Cheapest$116 | Average$212 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$124 | Average$416 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$150 | Average$472 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$191 | Average$406 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$238 | Average$456 | FlexibilityNo cancel fee | On-time63% |