He was educated at Uppingham School and the Royal Naval College, Dartmouth. He attended Sheffield University, graduating in 1976 with a degree in Electronic and Electrical Engineering.
Montgomery joined the Royal Navy in 1973. After spending his first three years of service at university, he went to sea and rose through the officer ranks to become Commander of HMS Beaver. Later he became Training Director of the Naval Recruiting and Training Agency and then Private Secretary to the Secretary of State for Defence.
He went on to become Director of Naval Personnel Strategy in 2005, Naval Secretary in 2008 and Second Sea Lord in 2010.
On 25 January 2013 the Home Office announced that Montgomery had been appointed Director General of the Border Force. Sir Charles Montgomery joined Border Force as Director General in March 2013.
He wears the Border Force uniform with the rank insignia of Director General.