AirHint found the following cheapest return flights from Seattle (SEA) to Belize City (BZE) in September 2025 (see full year).

Return flights

12 Sep - 20 Sep	United
26 Sep - 03 Oct	United
29 Sep - 02 Oct	United
29 Sep - 04 Oct	United
29 Sep - 06 Oct	United
29 Sep - 09 Oct	United
30 Sep - 03 Oct	United
30 Sep - 05 Oct	United
30 Sep - 07 Oct	United
30 Sep - 10 Oct	United
15 Sep - 22 Sep	United
12 Sep - 13 Sep	Alaska Airlines
28 Sep - 01 Oct	United

Also check the deals for one-way flights from Seattle to Belize City in September.

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 Seattle to Belize City in September from 334€

Return flights