40th Brigade may refer to:
British India 40th Indian Infantry Brigade
Russia/Soviet Union 40th Air Assault Brigade 40th Separate Guards Naval Infantry Brigade, a unit of the Russian Navy
Ukraine 40th Artillery Brigade (Ukraine) 40th Marine Brigade (Ukraine) 40th Tactical Aviation Brigade, an aviation unit of the Ukrainian Air Force
United Kingdom 40th Anti-Aircraft Brigade (United Kingdom) 40th Brigade (United Kingdom) 40th Brigade Royal Field Artillery
United States 40th Combat Aviation Brigade 40th Division Sustainment Brigade 40th Infantry Brigade Combat Team (United States), a unit of the United States Army
See also 40th Division (disambiguation) 40th Regiment (disambiguation) 40th Battalion (disambiguation) 40th Squadron (disambiguation)