The 4th Infantry Division, Philippine Army, known officially as the Diamond Division, is one of the Philippine Army's infantry units in Northern Mindanao.

On January 15, 1946, right after World War II, upon the reestablishment of the Commonwealth Government, all Military Districts were converted to military areas; Pursuant to Section 1 General Orders Number 46 of HAFP dated January 8, 1946. The 1st and 2nd Military Areas (IMA-IIMA) was in Luzon, while 3rd Military Area (IIIMA) in the Visayas, and the 4th Military Area (IVMA) in Mindanao. The remaining forces of the 10th MD were absorbed to Military Police Command (MPC) based at Camp Overton, Iligan.