42 Brigade provides administrative support for the British Army in the northwest of England. It controls 2 TA infantry Battallions, The Kings and Cheshire Regiment and the Lancastrian and Cumbrian Volunteers, as well as a number of smaller units. The 2 Regular Army Battalions within 42 Brigades area are under the operational control of 52 Infantry Brigade in Edinburgh.

The origins of the brigade can be traced back to the 42nd (East Lancashire) Division, formed as part of the Territorial Army in 1907 and which fought in World War I and World War II.