AirHint found the following cheapest one-way flights from Boston (BOS) to San Juan (SJU) in October 2025 (see full year).

One-Way flights

18 Oct	Spirit Airlines
21 Oct	Spirit Airlines
22 Oct	Spirit Airlines
01 Oct	Spirit Airlines
02 Oct	Spirit Airlines
25 Oct	Spirit Airlines
14 Oct	Spirit Airlines
16 Oct	Spirit Airlines
07 Oct	Spirit Airlines
04 Oct	Spirit Airlines

Also check the deals for return flights from Boston to San Juan in October.

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 one-way flights from Boston to San Juan in October from $108

One-Way flights