Cheap flights from Chicago to London (ORD to LHR) from $628

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

Shift your dates by a day or two: Mid-week departures (Tuesday–Wednesday) are almost always cheaper than weekend flights. Even shifting by one day can make a meaningful difference.

Direct flights are available: Direct flights take around 11h 8m and are worth it for convenience — but check if a one-stop flight is significantly cheaper before ruling it out.

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. Aer Lingus and Air Canada 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 Chicago to London start from $628, with typical prices ranging from $628 to $875.

The typical flight time from Chicago to London is approximately 11 hours and 8 minutes. Direct flights are available on this route.

Airlines operating this route include Aer Lingus, Air Canada, Air Serbia, Alaska Airlines, American Airlines, Austrian, British Airways, Brussels Airlines, Etihad Airways, Finnair.