18th Brigade

18th Brigade may refer to:


 * 18th Brigade (Australia), a unit of the Australian Army
 * 18th (Croatian) Eastern Bosnian Brigade, an irregular formation of Yugoslav partisans which opposed German forces during World War II
 * 18th Infantry Brigade (United Kingdom), a unit of the United Kingdom Army
 * 18th Mounted Brigade (United Kingdom)
 * 18th Engineer Brigade (United States), a unit of the United States Army
 * 18th Fires Brigade (United States), a unit of the United States Army
 * 18th Aviation Brigade (United States), a unit of the United States Army
 * 18th Military Police Brigade (United States), a unit of the United States Army