42nd Brigade or 42nd Infantry Brigade may refer to:
India 42nd Indian Brigade of the British Indian Army in the First World War
Ukraine 42nd Mechanized Brigade (Ukraine)
United Kingdom 42nd Anti-Aircraft Brigade (United Kingdom) 42nd Infantry Brigade (United Kingdom) 42nd Brigade Royal Field Artillery
United States 42nd Combat Aviation Brigade 42nd Infantry Division Sustainment Brigade 42nd Military Police Brigade
See also 42nd Division (disambiguation) 42nd Regiment (disambiguation) 42nd Squadron (disambiguation)