Frank Brandt was born in Madras, India on 2 October 1871, the son of Francis Brandt and Lucy Sophia Brandt (née Dobson). He joined the Royal Navy as a Cadet on 15 January 1885. He was promoted to Midshipman on 15 May 1887.

Promotion to Sub Lieutenant followed on 14 May 1891 and on 21 July 1892 he was appointed to HM Torpedo Boat No. 55. He was promoted to Lieutenant on 16 December 1892.  On 5 December 1896 he was appointed to the Cruiser HMS ECLIPSE as the Torpedo Officer.

On 31 December 1903 he was promoted to Commander, and, on 18 April 1906, he was appointed to the HMS MERCURY for duty with Submarine Boats, and in Command of the Portsmouth Flotilla. On 2nd April 1907 he was appointed to  HMS BONAVENTURE in Command and in Command of the Portsmouth Submarine Flotilla. On 17 November 1909 he was appointed to HMS MERCURY in Command of the Dover Submarine Flotilla.

Frank Brandt was promoted to the rank of Captain on 31 December 1909. He had intended to retire in 1910 but his application was refused so that his experience in submarines might not be lost. On 14 November 1910 he was appointed to the Submarine Depot Ship HMS BONAVENTURE in Command and for Command of the Portsmouth Submarine Flotilla.

Frank Brandt was appointed to the Cruiser HMS ECLIPSE in Command and for Trooping Duties on 24 February 1914 and, on 30 July 1914, he was appointed to the Cruiser HMS MONMOUTH in Command. HMS MONMOUTH took part in the Battle of Coronel on 1 November 1914 and the ship was lost with all hands.

Frank Brandt was the husband of Beryl Brandt (née Pennington) of Worthing, Sussex. He is commemorated on the Plymouth Naval War Memorial on Panel No. 1.