Leonard Belsey was born on 18 October 1884 at Ramsgate, Kent. He was the son of William and Caroline Belsey.

He joined the Royal Navy at HMS St VINCENT on 10 July 1900 as a Boy Seaman, being advanced to Boy 1st Class on 2 May 1901. He served in HM Ships AMPHITRITE, ANTRIM and THETIS before being rated Leading Seaman on 17 September 1910. He was advanced to Petty Officer on 20 January 1916.

In 1908 he married Annie Pay. After his death she was awarded his 1914-18 Star, British War Medal, Victory Medal and pension. He is commemorated on the Chatham Naval Memorial, panel 21, the war memorial at the Church of St Mary the Virgin, Ripple, Kent and the E49 memorial at Baltasound, Unst in the Shetlands.