Milne Force was a garrison Australian Army force formed in July 1942 during the World War II which controlled allied naval, land and air units in the region of Milne Bay, in the Territory of Papua. The force was responsible for constructing airstrips, roads, camps and defensive positions. Milne Force successfully withheld a Japanese invasion which landed on 25 August during the Battle of Milne Bay and forced the invasion force to retreat on 5 September. On 1 October 1942, Milne Force was redesignated the 11th Division.