'King I' was a US unrealised plan for an amphibious assault on and subsequent reconquest of Mindanao island in the Japanese-occupied Philippine islands group as the first step in General Douglas MacArthur’s 'Musketeer II' and 'King' plans for the reconquest of the Philippine islands group (late summer/autumn 1944).

Within this sequential plan, 'King I' was to have taken place at the southern end of Mindanao island on 15 November, 'King II' against Leyte island on 20 December, and 'King III' against the Zamboanga peninsula of Mindanao island on 7 December. After raids and reconnaissance had suggested that the Japanese defence of the Philippine islands group was lighter than had been anticipated, 'King I' was cancelled and recast as 'Victor V' for April 1945, 'King II' was brought forward to 20 October, and 'King III' was cancelled as recast as 'Victor IV' for April 1945.