20th Battalion

20th Battalion may refer to:


 * 20th Battalion (Australia), a World War I ANZAC battalion
 * 2/20th Battalion (Australia), a World War II Australian infantry battalion
 * 20th (Central Ontario) Battalion, CEF, a World War I battalion for the Canadian Corps
 * 20th Battalion, London Regiment (Blackheath and Woolwich)
 * 20th Battalion (New Zealand), a World War II infantry battalion