AirHint found the following cheapest return flights from Denver (DEN) to Bucharest (OTP) in December 2025 (see full year).

Return flights

01 Dec - 08 Dec	Icelandair
02 Dec - 27 Dec	Turkish Airlines
06 Dec - 27 Dec	Turkish Airlines
06 Dec - 30 Dec	Turkish Airlines
04 Dec - 17 Dec	Turkish Airlines
09 Dec - 30 Dec	Turkish Airlines
03 Dec - 27 Dec	jetBlue
01 Dec - 27 Dec	Turkish Airlines
02 Dec - 06 Jan	Frontier Airlines
01 Dec - 05 Jan	Frontier Airlines
17 Dec - 30 Jan	Frontier Airlines
16 Dec - 29 Jan	Frontier Airlines
18 Dec - 13 Jan	Frontier Airlines
18 Dec - 30 Jan	Frontier Airlines
17 Dec - 05 Jan	Frontier Airlines

Also check the deals for one-way flights from Denver to Bucharest 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 return flights from Denver to Bucharest in December from $539

Return flights