Cheap flights from London to Chicago (LHR to ORD) from $1,458

The cheapest month to fly is November, and departing on Wednesdays typically offers the best fares. Book 6–8 weeks ahead for the best prices.

Book at the right time: For international flights, aim to book 6–10 weeks ahead. Last-minute fares on London to Chicago are rarely cheap, and prices spike sharply within 2 weeks of departure.

Shift your dates by a day or two: Wednesdays are typically the cheapest day to fly this route. Avoiding Friday and Sunday departures can save significantly. November is historically the cheapest month on this route.

Weigh up connecting flights: Connecting flights on London to Chicago can be 20–40% cheaper than direct options. If you have time to spare, it's worth comparing.

Factor in baggage fees: Low-cost carriers on this route often advertise attractive base fares but charge separately for checked luggage. Always compare the all-in price — a $20 cheaper fare plus $50 baggage fee is no saving. Austrian and Aeromexico may have different inclusions, so check each airline's fare conditions.

Search in private browsing: Some booking sites use cookies to track repeat searches and may show higher prices after multiple lookups. Use an incognito or private window — or just use Booked AI, which pulls live prices without any tracking markup.

Compare two one-ways against a return: On some international routes, booking a one-way with one airline and the return with another can undercut a standard return ticket — especially if a budget carrier covers one direction. Check both options with the flexible dates calendar above.

The cheapest flights from London to Chicago start from $1,458, with typical prices ranging from $1,458 to $1,758.

The typical flight time from London to Chicago is approximately 13 hours and 13 minutes.

Airlines operating this route include Austrian, Aeromexico, American Airlines, Aer Lingus, Virgin Atlantic, Turkish Airlines, Avianca, TAP Air Portugal, Iberia, SAS, Finnair, Lufthansa, Etihad Airways, Icelandair, British Airways, SWISS, Air Canada, LOT Polish Airlines, Brussels Airlines.