[1] Khalilur Rahman was born on 1 January 1927 in Nandina, Jamalpur of Bengal Presidency then British India (now in Mymensingh, Bangladesh).

He later joined the Pakistan Military Academy in 1948 and commissioned in East Bengal Regiment in 1950.

He served as the general staff officer second grade at the CENTO Headquarters in Ankara, Turkey.

During the Bangladesh Liberation War, he was posted in General Headquarters as a Director of Defense Security Force.

He was the director general during the Assassination of Sheikh Mujibur Rahman, the president of Bangladesh.