84th Brigade may refer to:
British India 84th Indian Infantry Brigade
Russia/Soviet Union 84th Anti-Aircraft Rocket Brigade
Spain 84th Mixed Brigade
United Kingdom 84th Brigade (United Kingdom) 84th Brigade, Royal Field Artillery, a British Army unit in World War I 84th (East Anglian) Brigade, Royal Field Artillery, a British Army unit after World War I
See also 84th Division (disambiguation) 84th Regiment (disambiguation)