Sir John Emsley Fretwell, GCMG (15 June 1930 – 30 March 2017) was a British diplomat.
Fretwell was educated at Chesterfield Grammar School, the University of Lausanne and King's College, Cambridge.
He served in Hong Kong, Peking, Moscow and Washington, D.C., as Commercial Counsellor in Warsaw 1971–73, at the Foreign and Commonwealth Office in London as Head of the European Integration Department 1973–76 and as Assistant Under-Secretary 1976–79.
He was Minister in Washington, D.C. 1980–81, British Ambassador to France 1982–87 and Political Director and Deputy to the Permanent Under-Secretary of State for Foreign and Commonwealth Affairs 1987–90.
She was appointed OBE in the 2001 New Year Honours for services to pet owners and animal welfare.