London City
Chicago O'Hare Intl
2 stops
40h 35mMultiple Airlines
London Heathrow
Chicago O'Hare Intl
1 stop
31h 30mLOT
London Heathrow
Chicago O'Hare Intl
Nonstop
8h 50mLufthansa
London Heathrow
Chicago O'Hare Intl
1 stop
16h 00mTAP AIR PORTUGAL
London Gatwick
Chicago O'Hare Intl
1 stop
14h 15mIcelandair
London City
Chicago O'Hare Intl
2 stops
18h 45mMultiple Airlines
London Heathrow
Chicago O'Hare Intl
Nonstop
8h 55mChicago O'Hare Intl
London Heathrow
Nonstop
8h 15mLufthansa
London Gatwick
Chicago O'Hare Intl
1 stop
11h 20mChicago O'Hare Intl
London Gatwick
1 stop
10h 15mIcelandair
London Heathrow
Chicago O'Hare Intl
1 stop
15h 25mChicago O'Hare Intl
London Heathrow
1 stop
13h 40mLOT
London Heathrow
Chicago O'Hare Intl
1 stop
16h 20mChicago O'Hare Intl
London Heathrow
1 stop
16h 05mMultiple Airlines
London Heathrow
Chicago O'Hare Intl
1 stop
26h 20mChicago O'Hare Intl
London Heathrow
1 stop
18h 25mTAP AIR PORTUGAL
London Heathrow
Chicago O'Hare Intl
Nonstop
8h 40mChicago O'Hare Intl
London Heathrow
Nonstop
7h 45mFinnair
January
£1,593
February
£1,729
March
£1,898
April
£599
May
£1,994
June
£2,087
July
£965
August
£1,867
September
£1,964
October
£1,910
November
£2,021
December
£1,688
At the present moment the cheapest month to fly business class to Chicago is currently April; with June being the most expensive. Prices will vary depending on multiple factors such as booking in advance, airline and departure airports and times.