London City
Chicago O'Hare Intl
2 stops
40h 35mMultiple Airlines
London Heathrow
Chicago O'Hare Intl
1 stop
14h 40mLOT
London Heathrow
Chicago O'Hare Intl
Nonstop
9h 10mLufthansa
London Heathrow
Chicago O'Hare Intl
1 stop
16h 00mTAP AIR PORTUGAL
London Gatwick
Chicago O'Hare Intl
1 stop
14h 15mIcelandair
London Heathrow
Chicago O'Hare Intl
Nonstop
9h 05mBrussels Airlines
Manchester
Chicago O'Hare Intl
1 stop
35h 10mChicago O'Hare Intl
Manchester
1 stop
17h 05mTAP AIR PORTUGAL
Manchester
Chicago O'Hare Intl
1 stop
11h 10mChicago O'Hare Intl
Manchester
1 stop
10h 15mIcelandair
London Heathrow
Chicago O'Hare Intl
1 stop
14h 05mChicago O'Hare Intl
London Heathrow
Nonstop
7h 45mAmerican Airlines
London Heathrow
Chicago O'Hare Intl
Nonstop
9h 10mChicago O'Hare Intl
London Heathrow
Nonstop
8h 00mAustrian Airlines
London Heathrow
Chicago O'Hare Intl
1 stop
11h 15mChicago O'Hare Intl
London Heathrow
Nonstop
8h 00mUnited Airlines
London Heathrow
Chicago O'Hare Intl
1 stop
22h 50mChicago O'Hare Intl
London Heathrow
1 stop
19h 40mSWISS
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.