66th Brigade may refer to:
China 66th Brigade (China)
Ukraine 66th Mechanized Brigade (Ukraine)
United Kingdom 66th Anti-Aircraft Brigade 66th Infantry Brigade (United Kingdom) 66th Brigade, Royal Field Artillery, British Army unit during World War I 66th (South Midland) Brigade, Royal Field Artillery, British Army unit after World War I 66th (Leeds Rifles, The West Yorkshire Regiment) Anti-Aircraft Brigade, Royal Artillery
United States 66th Military Intelligence Brigade (United States) 66th Theater Aviation Command, an aviation brigade
See also 66th Division (disambiguation) 66th Regiment (disambiguation)