500th

500th may refer to:


 * 500th (1st Wessex) Field Company, Royal Engineers
 * 500th Air Defense Group, disbanded United States Air Force (USAF) organization
 * 500th Air Expeditionary Group Constituted as 500th Bombardment Group
 * 500th Bombardment Squadron, inactive United States Air Force unit
 * 500th Brigade, also known as the Kfir (Young Lion) Formation, a regular-service tank brigade from 1972 to 2003
 * 500th Fighter-Bomber Squadron, inactive United States Air Force unit
 * 500th Heavy Anti-Aircraft Regiment, Royal Artillery, a Scottish air defence unit of Britain's Territorial Army
 * 500th Military Intelligence Brigade (United States)
 * 500th Simpsons episode or At Long Last Leave, the 14th episode of the 23rd season of the American animated television series
 * 500th SS Parachute Battalion, the parachute unit of the Waffen-SS
 * Emmerdale Village's 500th anniversary, Emmerdale being a fictional village in the Yorkshire Dales in a British soap opera