Cheap flights from London to Chicago from £345

The cheapest month to fly to Chicago O'Hare Intl Airport from London is in September. Flight prices, which tend to average around £436, 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 during February instead. Flights to Chicago O'Hare Intl Airport in February, while not as cheap as those in September, still average around £438.

The cheapest day to depart from London 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 £610. Be sure to avoid booking your departure on a Saturday as prices are generally higher than usual. According to our data, the average ticket price to Chicago O'Hare Intl Airport on Saturday is £647.

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 £624. In contrast, the most expensive time of day to depart to Chicago O'Hare Intl Airport is in the afternoon when prices are around £658.

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

You are more likely to see cheaper flights to Chicago O'Hare Intl Airport from London when booking weeks ahead of your departure date. In general, you can expect to find flights to Chicago O'Hare Intl Airport for around £533 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 for as low as £505 on momondo.

There are 4 cabin classes available to choose from on London 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.

United Airlines, Icelandair, and Virgin Atlantic are the most popular carriers operating from London to Chicago O'Hare Intl

British Airways, Lufthansa and Icelandair are the top three most popular airlines that fly to Chicago O'Hare Intl Airport from London according to our data. British Airways is the first choice among our users, with 66% of people opting to fly with this airline when travelling to Chicago O'Hare Intl Airport. Keep in mind that there are 14 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 170 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.

Reykjavik (KEF) was the most common stop: 47% of momondo users choosing one-stop flights on this route connected there.

Flights via Zurich (ZRH) offer the lowest average return price of £430.

Flights connecting via Reykjavik (KEF) have the shortest average one-way travel time: 11h 15m.

Reykjavik (KEF) has the shortest average stopover time for this route: 1h 08m.

The number of flights available between London and Chicago O'Hare Intl Airport is 37 per day as of February 2026. The most frequent departure time is 14:00, with 55% of daily flights leaving in the afternoon.

The number of flights available between London and Chicago O'Hare Intl Airport is 263 per week as of February 2026. The most frequent departure day is Wed, with 16% of weekly flights leaving on this day.