Cheap flights from London to Chicago from $527

The month of September is, on average, the cheapest month to fly to Chicago from London, with most prices found around $597. If you’re not able to fly to Chicago in September, then February is your next best option. Flight prices from London to Chicago during February average around $687.

The cheapest day to depart on your flight to Chicago is on a Thursday when prices can be found for as low as $896. This is often the case because there is less demand to fly during this day of the week. When flying out on a Saturday, the most expensive travel day of the week, you can expect to see flight prices from London to Chicago for around $1,026.

Our most recent data shows that the best time of day to fly to Chicago is at noon. Flights from London to Chicago during this time can be as low as $907. In contrast, the most expensive time of day to depart to Chicago is in the afternoon when prices are around $947.

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

You are more likely to see cheaper flights to Chicago from London when booking weeks ahead of your departure date. In general, you can expect to find flights to Chicago for around $817 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Chicago from London for as low as $728 on momondo.

There are 4 cabin classes available to choose from on London to Chicago 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 11% on your flight if you consider stops on a London to Chicago flight.

As of July 2026, prices for London to Chicago flights are approximately 5% more expensive when compared to flights at the same time last year.

JetBlue, British Airways, and United Airlines are the most popular carriers operating from London to Chicago

British Airways, Lufthansa and American Airlines are the top three most popular airlines that fly to Chicago from London according to our data. British Airways is the first choice among our users, with 51% of people opting to fly with this airline when traveling to Chicago. Keep in mind that there are 7 different airlines that fly to Chicago on a routine basis, so you have a few additional options to choose from.

Historically, on average around 11% of flights between London and Chicago have experienced a delay on any given week. The average delay length over the past 12 months has been 177 minutes.

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

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

According to our data, United Airlines have had the least number of delays on this route over the last 12 months; with about 6% of their flights experiencing any sort of delay.

Reykjavik (KEF) was the most common stop: 82% of momondo users choosing 1-stop flights on this route connected there.

Flights via Reykjavik (KEF) offer the lowest average round-trip price of $539.

Flights connecting via Reykjavik (KEF) have the shortest average one-way travel time: 11h 25m.

Reykjavik (KEF) has the shortest average layover time for this route: 1h 03m.

As of July 2026, there are 52 flights per day flying from London to Chicago. The most common time of day flights depart is 2:00PM, with 52% of flights taking off in the afternoon.

364 flights are operational weekly from London to Chicago as of July 2026. The most popular departure day for this route is Mon, with 14% of flights per week taking off on this day.