Katharine Armstrong joined the Royal Navy as a Warfare Officer in 1996 after reading Biological Sciences at The University of Edinburgh. Her early career was spent at sea as a bridge watchkeeper in various classes of ship before navigating HMS Manchester. Subsequently, her second stage career jobs have been split between HR and Intelligence streams. The former has seen her employed in Navy Command HQ as both a Branch and Career Manager while latterly she has fulfilled intelligence assignments in Joint and MoD environments in addition to deployment overseas.

Mother of three boys and married to Rory, also a Royal Navy Officer, Katharine occasionally finds time to represent the Royal Navy and Combined Services in various sporting disciplines. She is a long-serving trustee of the Naval Service Sports Charity.

Commander Katharine Armstrong has been a Trustee of The Royal Navy and Royal Marines Charity since November 2008.