Sir Derek Malcolm Day (29 November 1927 – 7 March 2015) was a British diplomat and field hockey player who competed in the 1952 Summer Olympics. He was educated at Hurstpierpoint College and St Catharine’s College, Cambridge.

Field Hockey

A field hockey player, Day competed for Great Britain in the 1952 Summer Olympics winning a bronze medal and played club hockey for Southgate Hockey Club.

Diplomatic career