9th Infantry

9th Infantry may refer to:


 * 9th Bhopal Infantry, a regiment of the British Indian Army
 * 9th Infantry Brigade (Greece)
 * 9th Infantry Brigade (United Kingdom)
 * 9th Infantry Brigade (Lebanon)
 * 9th Infantry Division (Greece)
 * 9th Infantry Division (India), a formation of the British Indian Army
 * 9th Infantry Division (Philippines)
 * 9th Infantry Division (Poland)
 * 9th Infantry Division (South Korea)
 * 9th Infantry Division (United States)
 * 9th Infantry Regiment (United States)