129th may refer to:

• 129th (South Western) Brigade, British Territorial Force division formed in 1908
• 129th (Wentworth) Battalion, CEF, unit in the Canadian Expeditionary Force during the First World War
• 129th Delaware General Assembly, meeting of the legislative branch of the Delaware state government
• 129th Duke of Connaught's Own Baluchis, infantry regiment of the British Indian Army raised in 1846 as the 2nd Bellochee Battalion
• 129th Field Artillery Regiment (United States), regiment of the Field Artillery Branch of the United States Army
• 129th Illinois Volunteer Infantry Regiment, American infantry regiment that served in the Union Army during the American Civil War
• 129th Infantry Brigade (United Kingdom), 1st Line Territorial Army brigade during the Second World War
• 129th Infantry Division (Wehrmacht), Infantry Division of the German Army during World War II
• 129th Infantry Regiment (United States), United States military unit of the Illinois National Guard
• 129th Kentucky Derby or 2003 Kentucky Derby
• 129th meridian east, line of longitude across the Arctic Ocean, Asia, Australia, the Indian Ocean, the Southern Ocean and Antarctica
• 129th meridian west, line of longitude across the Arctic Ocean, North America, the Pacific Ocean, the Southern Ocean and Antarctica
• 129th Ohio General Assembly, the current legislative body of the state of Ohio for 2011 and 2012
• 129th Ohio Infantry (or 129th OVI), infantry regiment in the Union Army during the American Civil War
• 129th Regiment of Foot, infantry regiment of the British Army, created in 1794 and disbanded in 1796
• 129th Rescue Squadron, unit of the California Air National Guard
• 129th Rescue Wing, unit of the California Air National Guard
• 129th Strategic Reconnaissance Squadron, inactive United States Air Force unit
• 129th Street (IRT Third Avenue Line), massive station on the IRT Third Avenue Line in the New York City Subway system
• 129th Street (Manhattan), street in Manhattan
• 129th Toronto Scouting Group in Ontario, Canada
• Pennsylvania's 129th Representative District or Pennsylvania House of Representatives

See also[edit]

• 129 (number)
• AD 129, the year 129 (CXXIX) of the Julian calendar
• 129 BC