Thomas Baker was born at Teynham, Kent, in 1888Q4, the son of Jesse Baker, a farm labourer, and his second wife Sarah Ann (née French). He had a sister, and also six half-brothers and a half-sister.

He joined the Royal Navy at the Nore stokers’ training ship, HMS ACHERON, on 22 March 1909, giving his date of birth as 6 October 1889 and previous occupation as farm labourer.  Later that year he joined the armoured cruiser HMS SHANNON where he was rated Stoker 1st Class in May 1910.  In February 1911 he moved to the depot ship HMS ST GEORGE, and from June 1912 to July 1913 he served in the scout cruiser HMS BOADICEA.

On 5 July 1913 he joined the submarine depot ship HMS BONAVENTURE, and in September that year transferred to HMS MAIDSTONE, the principal depot ship of the Eighth Submarine Flotilla based at Harwich, for duty in E9. HMS E9 was commissioned in June 1914 and in October that year, commanded by Lt Cdr Max Horton, she entered the Baltic, together with HMS E1.  This was the start of a flotilla of eventually nine RN submarines operating from Reval (renamed Talinn after 1918) in support of the Russian Baltic Fleet.  On 1 January 1916 Thomas Baker was rated Acting Leading Stoker, and confirmed in the rate on 1 August.  E9 remained part of the Eighth Submarine Flotilla until August 1916 when administrative control of the Baltic submarines was transferred to HMS E19 (Cdr Francis Cromie).

Thomas Baker was awarded the Medal of the Order of St George 3rd Class by Russia.

According to his service record, he died on 24 February 1917 from septicaemia.  He is buried at Talinn Military Cemetery, Estonia. 

He left a widow, Sarah Ann Marks (née Giddins), whom he had married in February 1910 at Chatham.