Cheap flights from London Heathrow Airport to Chicago from $645

If you don’t want to visit Chicago in September, then you should wait until February to fly from London Heathrow Airport, when ticket prices are also cheap, with an average price of $863.

Our data shows that Friday is the least expensive day to fly to Chicago. Tickets to fly out on this day can be as low as $830. Flights from London Heathrow Airport to Chicago on a Saturday will generally be more expensive and average around $2,464. Keep in mind that these prices on both days could fluctuate depending on the season and the demand.

Our data shows that the cheapest London Heathrow Airport to Chicago flights are usually those with departure times at midday. Our users have found flights to Chicago at midday for as low as $1,128. Flights in the morning are often more expensive, with an average ticket price of $2,464.

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

You are more likely to see cheaper flights to Chicago from London Heathrow Airport when booking weeks ahead of your departure date. In general, you can expect to find flights to Chicago for around $1,034 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Chicago from London Heathrow Airport for as low as $970 on momondo.

There are 2 cabin classes available to choose from on London Heathrow 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 10% on your flight if you consider stops on a London Heathrow Airport to Chicago flight.

As of February 2026, prices for London Heathrow Airport to Chicago flights are approximately 20% more expensive when compared to flights at the same time last year.

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 169 minutes.

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

Thursday is statistically the day of the week that experiences the fewest delays on this flight route. Friday has historically seen more delays on average compared to the rest of the week.

According to our data, United Airlines have had the fewest delays on this route over the last 12 months, with about 5% of their flights experiencing any sort of delay.

As of February 2026, there are 37 flights per day flying from London Heathrow Airport to Chicago. The most common time of day flights depart is 12:00, with 65% of flights taking off in the afternoon.

The number of flights available between London Heathrow Airport and Chicago is 262 per week as of February 2026. The most frequent departure day is Wed, with 16% of weekly flights leaving on this day.