$62+ 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 7/23. Fares are subject to change and may not be available on all flights or dates of travel.
STL — MIA
Jun 11 — Jun 181
Round-trip
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 August, booked 33 days in advance, depart on a Sunday or Monday and return on a Thursday
Cheap flight deals from St. Louis to Key Largo
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Best
Last-minute
One-way
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 May 12, 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 May 12, 2026.
This Trip.com deal was found by Cheapflights users on 5/11. 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 5/258:08 pm
STL
- MIA
1 stop8h 25m
Frontier
Thu 5/2811:23 am
MIA
- STL
1 stop7h 10m
Frontier
Deal found 5/11![Frontier logo]()
$265
This Kiwi.com deal was found by Cheapflights users on 5/8. 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 6/195:06 pm
STL
- MIA
1 stop26h 29m
Frontier
Thu 6/255:26 pm
MIA
- STL
1 stop16h 26m
Frontier
Deal found 5/8![Frontier logo]()
$268
This Kiwi.com deal was found by Cheapflights users on 5/11. 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 6/15:27 pm
STL
- MIA
1 stop28h 20m
Frontier
Sat 6/65:22 pm
MIA
- STL
1 stop25h 11m
Frontier
Deal found 5/11![Frontier logo]()
$269
This Expedia deal was found by Cheapflights users on 5/8. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/236:30 pm
STL
- MIA
1 stop11h 30m
Frontier
Wed 5/276:30 am
MIA
- STL
1 stop13h 53m
Frontier
Deal found 5/8![Frontier logo]()
$270
This Kiwi.com deal was found by Cheapflights users on 5/9. 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 6/205:06 pm
STL
- MIA
1 stop5h 28m
Frontier
Mon 6/225:26 pm
MIA
- STL
1 stop25h 04m
Frontier
Deal found 5/9![Frontier logo]()
$272
This Kiwi.com deal was found by Cheapflights users on 5/10. 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 6/65:27 pm
STL
- MIA
2 stops25h 47m
Frontier
Fri 6/196:20 am
MIA
- STL
1 stop12h 58m
Frontier
Deal found 5/10![Frontier logo]()
$274
This Delta deal was found by Cheapflights users on 5/8. 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 6/96:21 am
STL
- MIA
1 stop6h 14m
Delta
Tue 6/168:15 am
MIA
- STL
1 stop8h 35m
Delta
Deal found 5/8![Delta logo]()
$275
This American Airlines deal was found by Cheapflights users on 5/7. 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.
Sat 9/192:12 pm
STL
- MIA
Nonstop2h 52m
American Airlines
Mon 9/2111:22 am
MIA
- STL
Nonstop3h 00m
American Airlines
Deal found 5/7![American Airlines logo]()
$277
This Trip.com deal was found by Cheapflights users on 5/12. 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 6/38:08 pm
STL
- MIA
1 stop8h 25m
Frontier
Sun 6/78:10 am
MIA
- STL
1 stop10h 23m
Frontier
Deal found 5/12![Frontier logo]()
$278
This Kiwi.com deal was found by Cheapflights users on 5/11. 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 6/256:31 pm
STL
- MIA
2 stops23h 56m
Frontier
Wed 7/17:00 am
MIA
- STL
1 stop12h 18m
Frontier
Deal found 5/11![Frontier logo]()
$279
This Frontier deal was found by Cheapflights users on 5/9. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/236:30 pm
STL
- MIA
1 stop11h 30m
Frontier
Sat 5/306:30 am
MIA
- STL
1 stop13h 53m
Frontier
Deal found 5/9![Frontier logo]()
$280
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 May 12, 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 May 12, 2026.
This Delta deal was found by Cheapflights users on 5/7. 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 6/99:21 am
STL
- MIA
1 stop4h 34m
Delta
Tue 6/161:38 pm
MIA
- STL
1 stop8h 01m
Delta
Deal found 5/7![Delta logo]()
$285
This Southwest deal was found by Cheapflights users on 5/7. 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 8/314:55 pm
STL
- MIA
1 stop4h 10m
Southwest
Wed 9/99:15 am
MIA
- STL
2 stops9h 40m
Southwest
Deal found 5/7![Southwest logo]()
$290
This United Airlines deal was found by Cheapflights users on 5/11. 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 7/141:13 pm
STL
- MIA
1 stop8h 14m
United Airlines
Wed 7/151:10 pm
MIA
- STL
2 stops9h 16m
United Airlines
Deal found 5/11![United Airlines logo]()
$415
This Southwest deal was found by Cheapflights users on 5/8. 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 7/223:30 pm
STL
- MIA
1 stop5h 40m
Southwest
Sun 8/25:50 am
MIA
- STL
Nonstop2h 50m
Southwest
Deal found 5/8![Southwest logo]()
$347
This Southwest deal was found by Cheapflights users on 5/8. 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 7/55:50 am
STL
- MIA
2 stops7h 40m
Southwest
Sat 7/116:10 am
MIA
- STL
2 stops10h 10m
Southwest
Deal found 5/8![Southwest logo]()
$373
This United Airlines deal was found by Cheapflights users on 5/8. 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 7/286:00 am
STL
- MIA
2 stops9h 16m
United Airlines
Tue 8/48:48 am
MIA
- STL
2 stops13h 38m
United Airlines
Deal found 5/8![United Airlines logo]()
$466
This Southwest deal was found by Cheapflights users on 5/7. 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 6/213:55 pm
STL
- MIA
Nonstop2h 45m
Southwest
Fri 6/267:15 am
MIA
- STL
Nonstop2h 50m
Southwest
Deal found 5/7![Southwest logo]()
$419
This Southwest deal was found by Cheapflights users on 5/10. 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 10/305:35 am
STL
- MIA
2 stops11h 50m
Southwest
Tue 11/36:50 am
MIA
- STL
2 stops8h 00m
Southwest
Deal found 5/10![Southwest logo]()
$444
This Southwest deal was found by Cheapflights users on 5/7. 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 6/52:30 pm
STL
- MIA
2 stops6h 35m
Southwest
Sun 6/75:35 am
MIA
- STL
2 stops9h 30m
Southwest
Deal found 5/7![Southwest logo]()
$450
This Southwest deal was found by Cheapflights users on 5/9. 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.
Thu 6/252:30 pm
STL
- MIA
2 stops6h 35m
Southwest
Mon 6/295:25 am
MIA
- STL
2 stops7h 45m
Southwest
Deal found 5/9![Southwest logo]()
$450
This Southwest deal was found by Cheapflights users on 5/8. 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
Sun 6/145:50 am
MIA
- STL
Nonstop2h 50m
Southwest
Deal found 5/8![Southwest logo]()
$460
Last-minute flights from St. Louis to Key LargoDiscover last-minute flight deals from St. Louis to Key Largo. Data last updated May 12, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Key Largo. Data last updated May 12, 2026 and is based on user searches.
This Expedia deal was found by Cheapflights users on 5/8. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/236:30 pm
STL
- MIA
1 stop11h 30m
Frontier
Wed 5/276:30 am
MIA
- STL
1 stop13h 53m
Frontier
Deal found 5/8![Frontier logo]()
$270
This Frontier deal was found by Cheapflights users on 5/9. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/236:30 pm
STL
- MIA
1 stop11h 30m
Frontier
Sat 5/306:30 am
MIA
- STL
1 stop13h 53m
Frontier
Deal found 5/9![Frontier logo]()
$280
This Trip.com deal was found by Cheapflights users on 5/11. 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 5/258:08 pm
STL
- MIA
1 stop8h 25m
Frontier
Thu 5/2811:23 am
MIA
- STL
1 stop7h 10m
Frontier
Deal found 5/11![Frontier logo]()
$265
This Kiwi.com deal was found by Cheapflights users on 5/11. 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 6/15:27 pm
STL
- MIA
1 stop28h 20m
Frontier
Sat 6/65:22 pm
MIA
- STL
1 stop25h 11m
Frontier
Deal found 5/11![Frontier logo]()
$269
This Trip.com deal was found by Cheapflights users on 5/12. 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 6/38:08 pm
STL
- MIA
1 stop8h 25m
Frontier
Sun 6/78:10 am
MIA
- STL
1 stop10h 23m
Frontier
Deal found 5/12![Frontier logo]()
$278
This Kiwi.com deal was found by Cheapflights users on 5/10. 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 6/65:27 pm
STL
- MIA
2 stops25h 47m
Frontier
Fri 6/196:20 am
MIA
- STL
1 stop12h 58m
Frontier
Deal found 5/10![Frontier logo]()
$274
This Kiwi.com deal was found by Cheapflights users on 5/10. 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 6/76:33 pm
STL
- MIA
1 stop27h 14m
Frontier
Wed 6/1711:19 am
MIA
- STL
2 stops13h 30m
Frontier
Deal found 5/10![Frontier logo]()
$282
This Delta deal was found by Cheapflights users on 5/8. 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 6/96:21 am
STL
- MIA
1 stop6h 14m
Delta
Tue 6/168:15 am
MIA
- STL
1 stop8h 35m
Delta
Deal found 5/8![Delta logo]()
$275
This Kiwi.com deal was found by Cheapflights users on 5/8. 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 6/195:06 pm
STL
- MIA
1 stop26h 29m
Frontier
Thu 6/255:26 pm
MIA
- STL
1 stop16h 26m
Frontier
Deal found 5/8![Frontier logo]()
$268
This Kiwi.com deal was found by Cheapflights users on 5/9. 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 6/205:06 pm
STL
- MIA
1 stop5h 28m
Frontier
Mon 6/225:26 pm
MIA
- STL
1 stop25h 04m
Frontier
Deal found 5/9![Frontier logo]()
$272
This Kiwi.com deal was found by Cheapflights users on 5/11. 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 6/256:31 pm
STL
- MIA
2 stops23h 56m
Frontier
Fri 7/36:20 am
MIA
- STL
1 stop12h 58m
Frontier
Deal found 5/11![Frontier logo]()
$279
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 May 12, 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 May 12, 2026.
This Kiwi.com deal was found by Cheapflights users on 5/11. 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 7/236:33 pm
STL
- MIA
1 stop27h 32m
Frontier
Deal found 5/11![Frontier logo]()
$62
This Kiwi.com deal was found by Cheapflights users on 5/10. 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 6/55:27 pm
STL
- MIA
1 stop28h 20m
Frontier
Deal found 5/10![Frontier logo]()
$63
This Kiwi.com deal was found by Cheapflights users on 5/8. 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 7/114:52 pm
STL
- MIA
1 stop20h 01m
Frontier
Deal found 5/8![Frontier logo]()
$64
This Kiwi.com deal was found by Cheapflights users on 5/11. 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 7/64:52 pm
STL
- MIA
1 stop20h 01m
Frontier
Deal found 5/11![Frontier logo]()
$65
This Kiwi.com deal was found by Cheapflights users on 5/8. 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 7/15:06 pm
STL
- MIA
1 stop28h 57m
Frontier
Deal found 5/8![Frontier logo]()
$70
This Kiwi.com deal was found by Cheapflights users on 5/11. 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 7/56:33 pm
STL
- MIA
1 stop21h 00m
Frontier
Deal found 5/11![Frontier logo]()
$81
This Kiwi.com deal was found by Cheapflights users on 5/11. 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 8/74:52 pm
STL
- MIA
1 stop26h 37m
Frontier
Deal found 5/11![Frontier logo]()
$94
This Kiwi.com deal was found by Cheapflights users on 5/8. 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 6/216:31 pm
STL
- MIA
1 stop21h 00m
Frontier
Deal found 5/8![Frontier logo]()
$98
This Kiwi.com deal was found by Cheapflights users on 5/11. 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 7/45:06 pm
STL
- MIA
1 stop28h 59m
Frontier
Deal found 5/11![Frontier logo]()
$100
This Kiwi.com deal was found by Cheapflights users on 5/11. 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 6/76:33 pm
STL
- MIA
2 stops14h 54m
Frontier
Deal found 5/11![Frontier logo]()
$101
This Kiwi.com deal was found by Cheapflights users on 5/9. 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 7/76:33 pm
STL
- MIA
2 stops26h 46m
Frontier
Deal found 5/9![Frontier logo]()
$102
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 May 12, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $265 (Trip.com) |
One-way from | $62 (Kiwi.com) |
Popular in | March |
Cheapest in | September |
Average price | $431 |
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 May 12, 2026.
Use the filters below to find and compare flights from St. Louis to Key Largo that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
St. LouisMiami
STL - MIA
STLMIA
Lambert-St Louis
Tue 6/9
9:21 am-2:55 pm
1 stop4h 34m
Miami
Tue 6/16
1:38 pm-8:39 pm
1 stop8h 01m
$285
St. LouisMiami
STL - MIA
STLMIA
Lambert-St Louis
Mon 8/31
4:55 pm-10:05 pm
1 stop4h 10m
Miami
Wed 9/9
9:15 am-5:55 pm
2 stops9h 40m
$290
St. LouisMiami
STL - MIA
STLMIA
Lambert-St Louis
Wed 7/22
3:30 pm-10:10 pm
1 stop5h 40m
Miami
Sun 8/2
5:50 am-7:40 am
Nonstop2h 50m
$347
St. LouisMiami
STL - MIA
STLMIA
Lambert-St Louis
Sun 7/5
5:50 am-2:30 pm
2 stops7h 40m
Miami
Sat 7/11
6:10 am-3:20 pm
2 stops10h 10m
$373
St. LouisMiami
STL - MIA
STLMIA
Lambert-St Louis
Tue 7/14
1:13 pm-10:27 pm
1 stop8h 14m
Miami
Wed 7/15
1:10 pm-9:26 pm
2 stops9h 16m
$415
Quickest round-trip
St. LouisMiami
STL - MIA
STLMIA
Lambert-St Louis
Sun 6/21
3:55 pm-7:40 pm
Nonstop2h 45m
Miami
Fri 6/26
7:15 am-9:05 am
Nonstop2h 50m
$419
St. LouisMiami
STL - MIA
STLMIA
Lambert-St Louis
Fri 10/30
5:35 am-6:25 pm
2 stops11h 50m
Miami
Tue 11/3
6:50 am-1:50 pm
2 stops8h 00m
$444
St. LouisMiami
STL - MIA
STLMIA
Lambert-St Louis
Fri 6/5
2:30 pm-10:05 pm
2 stops6h 35m
Miami
Sun 6/7
5:35 am-2:05 pm
2 stops9h 30m
$450
St. LouisMiami
STL - MIA
STLMIA
Lambert-St Louis
Thu 6/25
2:30 pm-10:05 pm
2 stops6h 35m
Miami
Mon 6/29
5:25 am-12:10 pm
2 stops7h 45m
$450
St. LouisMiami
STL - MIA
STLMIA
Lambert-St Louis
Sun 6/7
3:55 pm-7:40 pm
Nonstop2h 45m
Miami
Sun 6/14
5:50 am-7:40 am
Nonstop2h 50m
$460
Showing 1-10 of 20 resultsSorted by cheapest first
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
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 May 12, 2026.
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?
Use this chart to determine the cheapest time to fly round-trip from St. Louis to Key Largo. Price data was last updated on May 9, 2026.
Travelers seeking maximum savings on their St. Louis to Key Largo flight should consider departing on Tuesday at noon when fares are most often at their lowest. Thursday 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 May 12, 2026.
The most flights from STL to KE9 are scheduled on a Friday (6 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (3 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 May 12, 2026.
Peruse reviews from past customers who have flown with Southwest,Delta, andAmerican 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.
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Food
7.0
Crew
8.6
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Food
7.0
Crew
8.6
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Food
7.0
Crew
8.6
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Food
7.0
Crew
8.6
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Food
7.0
Crew
8.6
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Food
7.0
Crew
8.6
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
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
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Complete your trip
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Search flights from St. Louis to Key Largo by cabin class
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St. Louis and Key Largo flights
Browse other St. Louis and Key Largo flight options. Last updated on May 12, 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 May 12, 2026.
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St. Louis to Key Largo flights
Consider these flights traveling from St. Louis to Key Largo.
Top 7 airlines flying from St. Louis to Key Largo
Discover the top 7 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 May 12, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$63 | Average$149 | FlexibilityNo cancel fee | On-time65% | |
| Cheapest$127 | Average$220 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$150 | Average$455 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$162 | Average$383 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$178 | Average$417 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$220 | Average$414 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$233 | Average$451 | FlexibilityNo cancel fee | On-time63% |