AirHint found the following cheapest one-way flights from Chicago (MDW) to London (LHR) in December 2025 (see full year).

One-Way flights

03 Dec	Frontier Airlines
07 Dec	Frontier Airlines
31 Dec	Virgin Atlantic
01 Dec	Air France
02 Dec	Air France
05 Dec	Virgin Atlantic
12 Dec	Virgin Atlantic
15 Dec	Delta
17 Dec	Porter Airlines (Canada) Ltd
25 Dec	Delta

Also check the deals for return flights from Chicago to London 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.

Book a cheap hotel in London

Cheap car rent in London

Cheapest one-way flights from Chicago to London in December from 271€

One-Way flights