He was educated at Harrow School and the University of Cambridge and was called to the bar at the Inner Temple. At the age of 16 he lost the use of his right arm. In 1927 he married Hester Harriot, eldest daughter of Major-General Sir Reginald Pinney.
From 1928 until his death he was a Municipal Reform Party (later Conservative Party) member of Chelsea Borough Council until his death, and served as Mayor of Chelsea for two consecutive terms in 1957-59.
He was also a long-term member of the London County Council, elected unopposed to fill a casual vacancy in the representation of Chelsea on 23 February 1933. He was re-elected twice, retiring from the county council at the 1946 elections.
He was awarded the OBE in the 1944 Birthday Honours for his work as "Adviser to Postal and Telegraph Censorship, Ministry of Economic Warfare".
Details of a diary, held at the Imperial War Museum, here.
- "Obituary: Mr Basil Marsden-Smedley". The Times: p. 12. 8 September 1964.
- The marriage of Basil Futvoye Marsden-Smedley to Miss Hester Harriot Pinney. The Lafayette Negative Catalogue. Victoria and Albert Museum.
- London Gazette: . 10 June 1944.