AirHint found the following cheapest return flights from Chicago (ORD) to Brussels (BRU) in December 2025 (see full year).

Return flights

24 Dec - 07 Jan	Scandinavian Airlines
27 Dec - 29 Dec	Scandinavian Airlines
28 Dec - 08 Jan	Scandinavian Airlines
21 Dec - 07 Jan	Icelandair
19 Dec - 10 Jan	Frontier Airlines
30 Dec - 04 Jan	LOT
20 Dec - 27 Dec	Arajet
19 Dec - 28 Dec	Frontier Airlines
24 Dec - 07 Jan	Brussels Airlines	direct
28 Dec - 08 Jan	Brussels Airlines	direct
30 Dec - 04 Jan	Brussels Airlines	direct
21 Dec - 07 Jan	Brussels Airlines	direct
19 Dec - 02 Jan	Frontier Airlines
20 Dec - 27 Dec	Brussels Airlines	direct
19 Dec - 28 Dec	Lufthansa	direct
27 Dec - 29 Dec	Brussels Airlines	direct

Also check the deals for one-way flights from Chicago to Brussels 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 Chicago to Brussels in December from $822

Return flights