AirHint found the following cheapest return flights from Denver (DEN) to Chicago (ORD) in October 2025 (see full year).

Return flights

14 Oct - 18 Oct	Frontier Airlines	direct
10 Oct - 13 Oct	Frontier Airlines	direct
24 Oct - 27 Oct	Frontier Airlines	direct
09 Oct - 12 Oct	Frontier Airlines	direct
13 Oct - 17 Oct	Frontier Airlines	direct
11 Oct - 14 Oct	Frontier Airlines	direct
12 Oct - 02 Nov	Sun Country Airlines

Also check the deals for one-way flights from Denver to Chicago 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.

Book a cheap hotel in Chicago

Cheap car rent in Chicago

Cheapest return flights from Denver to Chicago in October from $108

Return flights