AirHint found the following cheapest one-way flights from Denver (DEN) to San Juan (SJU) in August 2025 (see full year).

One-Way flights

07 Aug	Frontier Airlines
02 Aug	Frontier Airlines
03 Aug	Frontier Airlines
19 Aug	Frontier Airlines
24 Aug	Frontier Airlines
25 Aug	Frontier Airlines
30 Aug	Frontier Airlines
26 Aug	Frontier Airlines
01 Aug	Frontier Airlines
30 Aug	United	direct

Also check the deals for return flights from Denver to San Juan in August.

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 Denver to San Juan in August from 114€

One-Way flights