Cheap flights from London Heathrow Airport to Chicago from £348

The cheapest month to fly to Chicago O'Hare Intl Airport from London Heathrow Airport is in September. Flight prices, which tend to average around £435, are often lower during this time because this is during the off-season. If you aren’t able to travel during the month of September, then book flights to Chicago O'Hare Intl Airport from London Heathrow Airport during February instead. Flights to Chicago O'Hare Intl Airport in February, while not as cheap as those in September, still average around £446.

The cheapest day to depart from London Heathrow Airport to Chicago O'Hare Intl Airport is on a Wednesday. Travellers who choose to depart for Chicago O'Hare Intl Airport on a Wednesday will often find tickets for as low as £623. Be sure to avoid booking your departure on a Sunday as prices are generally higher than usual. According to our data, the average ticket price to Chicago O'Hare Intl Airport on Sunday is £663.

The cheapest time of day to fly to Chicago O'Hare Intl Airport is at midday when flights can be purchased for as low as £634. In contrast, the most expensive time of day to depart to Chicago O'Hare Intl Airport is in the afternoon when prices are around £669.

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

You are more likely to see cheaper flights to Chicago O'Hare Intl Airport from London Heathrow Airport when booking weeks ahead of your departure date. In general, you can expect to find flights to Chicago O'Hare Intl Airport for around £552 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Chicago O'Hare Intl Airport from London Heathrow Airport for as low as £463 on momondo.

There are 4 cabin classes available to choose from on London Heathrow to Chicago O'Hare Intl 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 6% on your flight if you consider stops on a London Heathrow Airport to Chicago O'Hare Intl Airport flight.

As of March 2026, prices for London Heathrow Airport to Chicago O'Hare Intl Airport flights are approximately 3% cheaper when compared to flights at the same time last year.

Icelandair, JetBlue, and SWISS are the most popular carriers operating from London Heathrow to Chicago O'Hare Intl

British Airways, Lufthansa and United Airlines are the top three most popular airlines that fly to Chicago O'Hare Intl Airport from London Heathrow Airport according to our data. British Airways is the first choice among our users, with 65% of people opting to fly with this airline when travelling to Chicago O'Hare Intl Airport. Keep in mind that there are 15 different airlines that fly to Chicago O'Hare Intl Airport 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 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.

Dublin (DUB) was the most common stop: 38% of momondo users choosing one-stop flights on this route connected there.

Flights via Zurich (ZRH) offer the lowest average return price of £438.

Flights connecting via Dublin (DUB) have the shortest average one-way travel time: 11h 34m.

Frankfurt am Main (FRA) has the shortest average stopover time for this route: 1h 15m.

The number of flights available between London Heathrow Airport and Chicago O'Hare Intl Airport is 37 per day as of March 2026. The most frequent departure time is 12:00, with 60% of daily flights leaving in the afternoon.

265 flights are operational weekly from London Heathrow Airport to Chicago O'Hare Intl Airport as of March 2026. The most popular departure day for this route is Wed, with 16% of flights per week taking off on this day.