Cheap flights from Chicago to London from $321

The cheapest month to fly to London from Chicago is in January. Flight prices, which tend to average around $623, are often lower during this time because this is during the off-season. The month of February is another great option to travel to London, with average flight prices from Chicago averaging around $698.

The cheapest day to depart from Chicago to London is on a Tuesday. Travelers who choose to depart for London on a Tuesday will often find tickets for as low as $923. If your travel schedule is flexible, try to avoid departing on a Saturday because tickets tend to average around $1,139. These prices are subject to change though, so be sure to set up a Price Alert for flights to London.

Flying to London from Chicago in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as $1,002 when looking at flights departing in the afternoon. Flights to London are more costly in the evening, with an average ticket price of $1,057. Departure times in the evening fall within the peak daily travel times, which is why tickets can be more expensive.

Fly from Chicago O'Hare Intl to London Heathrow for the best Chicago - London flight prices

You are more likely to see cheaper flights to London from Chicago when booking weeks ahead of your departure date. In general, you can expect to find flights to London for around $926 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to London from Chicago for as low as $862 on momondo.

There are 4 cabin classes available to choose from on Chicago to London flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

You could potentially save up to 41% on your flight if you consider stops on a Chicago to London flight.

As of October 2026, prices for Chicago to London flights are approximately 42% more expensive when compared to flights at the same time last year.

United Airlines, TAP AIR PORTUGAL, and Icelandair are the most popular carriers operating from Chicago to London

British Airways, American Airlines and United Airlines are the top three most popular airlines that fly to London from Chicago according to our data. British Airways is the first choice among our users, with 41% of people opting to fly with this airline when traveling to London. Keep in mind that there are 13 different airlines that fly to London on a routine basis, so you have a few additional options to choose from.

Historically, on average around 23% of flights between Chicago and London have experienced a delay on any given week. The average delay length over the past 12 months has been 161 minutes.

Generally, flights departing in the early afternoon tend to experience fewer delays. Flights at night have, in the past, seen delays more frequently in comparison.

Tuesday is statistically the day of the week which experiences the fewest number of delays on this flight route. Sunday has historically seen more delays on average compared to the rest of the week.

According to our data, American Airlines have had the least number of delays on this route over the last 12 months; with about 22% of their flights experiencing any sort of delay.

Reykjavik (KEF) was the most common stop: 46% of momondo users choosing 1-stop flights on this route connected there.

Flights via Zurich (ZRH) offer the lowest average round-trip price of $105.

Flights connecting via Amsterdam (AMS) have the shortest average one-way travel time: 9h 45m.

Reykjavik (KEF) has the shortest average layover time for this route: 0h 55m.

As of October 2026, there are 35 flights per day flying from Chicago to London. The most common time of day flights depart is 10:00PM, with 81% of flights taking off in the evening.

247 flights are operational weekly from Chicago to London as of October 2026. The most popular departure day for this route is Mon, with 17% of flights per week taking off on this day.