AirHint found the following cheapest return flights from Trenton (TTN) to San Juan (SJU) in October 2025 (see full year).

Return flights

16 Oct - 22 Oct	Frontier Airlines
16 Oct - 19 Oct	Frontier Airlines
25 Oct - 27 Oct	Frontier Airlines
23 Oct - 27 Oct	Frontier Airlines
03 Oct - 06 Oct	Frontier Airlines
04 Oct - 08 Oct	Frontier Airlines
10 Oct - 17 Oct	Frontier Airlines
17 Oct - 19 Oct	Frontier Airlines
30 Oct - 06 Nov	Frontier Airlines
30 Oct - 02 Nov	Frontier Airlines
19 Oct - 24 Oct	Frontier Airlines
02 Oct - 06 Oct	Frontier Airlines

Also check the deals for one-way flights from Trenton 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 return flights from Trenton to San Juan in October from $252

Return flights