AirHint found the following cheapest return flights from Miami (MIA) to Castries (SLU) in December 2025 (see full year).

Return flights

12 Dec - 17 Dec	American Airlines	direct
04 Dec - 07 Dec	Caribbean Airlines
23 Dec - 30 Dec	American Airlines
30 Dec - 05 Jan	American Airlines	direct
18 Dec - 07 Jan	Caribbean Airlines
30 Dec - 02 Jan	Caribbean Airlines
23 Dec - 27 Dec	Caribbean Airlines
26 Dec - 30 Dec	Copa

Also check the deals for one-way flights from Miami to Castries in December.

The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.

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Cheapest return flights from Miami to Castries in December from $517

Return flights