AirHint found the following cheapest one-way flights from Newark (EWR) to San Juan (SJU) in December 2025 (see full year).

One-Way flights

09 Dec	Frontier Airlines	direct
06 Dec	Frontier Airlines	direct
03 Dec	Frontier Airlines	direct
08 Dec	United	direct
04 Dec	Frontier Airlines	direct
13 Dec	Frontier Airlines	direct
12 Dec	Frontier Airlines	direct
15 Dec	Frontier Airlines	direct
16 Dec	Frontier Airlines	direct
07 Dec	Frontier Airlines	direct

Also check the deals for return flights from Newark to San Juan 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 one-way flights from Newark to San Juan in December from $66

One-Way flights