Cheapest one-way flights from Boston to San Juan in September from $84

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

One-Way flights

18 Sep Frontier Airlines
08 Sep Frontier Airlines
25 Sep Frontier Airlines
28 Sep Frontier Airlines
24 Sep Spirit Airlines
13 Sep Spirit Airlines
20 Sep Spirit Airlines
17 Sep Spirit Airlines
01 Sep Spirit Airlines
03 Sep Spirit Airlines

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

Skyscanner

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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