Cheap flights from St. Louis to Key Largo from CA $102

View CA $102 flight on Thu, Aug. 14, 2025Opens in a new window

Popular airlines from St. Louis to Key Largo

  • Plan, book, fly with confidence

  • trending down icon

    Be in the know

    Get alerts if flight prices drop or rise*
  • bex rewards loyalty icon

    Book smarter

    Save up to 30% on select hotels after you book a flight*
  • payments icon

    Earn twice

    Earn your airline miles on top of our rewards
    Sign in

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

Prices were available within the past 7 days and start at CA $102 for one-way flights and CA $691 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

American Airlines
Thu, Jul. 24 - Thu, Aug. 7
STL
St. Louis
MIA
Miami
CA $691 Roundtrip, found 4 hours ago
CA $691
Roundtrip
found 4 hours ago
Select American Airlines flight, departing Thu, Jul. 24 from St. Louis to Miami, returning Thu, Aug. 7, priced at CA $691 found 4 hours ago
American Airlines
Thu, Jul. 24 - Thu, Aug. 7
STL
St. Louis
MIA
Miami
CA $701 Roundtrip, found 4 hours ago
CA $701
Roundtrip
found 4 hours ago
Select American Airlines flight, departing Thu, Jul. 24 from St. Louis to Miami, returning Thu, Aug. 7, priced at CA $701 found 4 hours ago
American Airlines
Thu, Jul. 24 - Thu, Aug. 7
STL
St. Louis
MIA
Miami
CA $715 Roundtrip, found 4 hours ago
CA $715
Roundtrip
found 4 hours ago
Select American Airlines flight, departing Thu, Jul. 24 from St. Louis to Miami, returning Thu, Aug. 7, priced at CA $715 found 4 hours ago
Delta
Thu, Jul. 24 - Thu, Aug. 7
STL
St. Louis
MIA
Miami
CA $764 Roundtrip, found 4 hours ago
CA $764
Roundtrip
found 4 hours ago
Select Delta flight, departing Thu, Jul. 24 from St. Louis to Miami, returning Thu, Aug. 7, priced at CA $764 found 4 hours ago
Delta
Thu, Jul. 24 - Thu, Aug. 7
STL
St. Louis
MIA
Miami
CA $766 Roundtrip, found 4 hours ago
CA $766
Roundtrip
found 4 hours ago
Select Delta flight, departing Thu, Jul. 24 from St. Louis to Miami, returning Thu, Aug. 7, priced at CA $766 found 4 hours ago
American Airlines
Thu, Jul. 24 - Thu, Aug. 7
STL
St. Louis
MIA
Miami
CA $776 Roundtrip, found 4 hours ago
CA $776
Roundtrip
found 4 hours ago
Select American Airlines flight, departing Thu, Jul. 24 from St. Louis to Miami, returning Thu, Aug. 7, priced at CA $776 found 4 hours ago

Find the cheapest month to fly from St. Louis (STL) to Miami (MIA)

September is typically the cheapest month to fly

From CA $183 - CA $310 per traveller.

Graph displaying average flight prices per month

*Available to Expedia members.