Christopher Segar was born 25 November 1950, the son of Cyril John Segar and Margery (née Angliss). He was educated at Sevenoaks School and then Sidney Sussex College, University of Cambridge.

[After a short time with VSO in Cameroun, 1969, Segar joined the Foreign and Commonwealth Office in 1973 and his diplomatic career included: Reporting Officer, UKMis New York [United States], 1973; Energy Department, FCO, 1974; MECAS, 1974–76; Third, later Second Secretary, Dubai, 1976–79; Middle East Department, FCO, 1979-82; South East Asia Department, FCO, 1982-83; Head of Chancery and Consul, Luanda [Angola], 1984–87; UK Delegation to OECD, Paris [France], 1987–90; Deputy Head of Mission and Consul General, Baghdad [Iraq], 1990–91; on secondment to MoD as Middle East Director in Defence Sales, 1991–94; Commercial Counsellor, Riyadh [Saudi Arabia], 1994–97 and Beijing [China], 1997–2001; Head of Aviation, Maritime, Science and Energy Department, subsequently Aviation, Maritime and Energy Department, FCO, 2001–03; seconded to Iraq Policy Unit, February 2003; Head of British Office, Baghdad, 2003–04.

Following his early retirement from the FCO, after a spell at the Centre for Studies in Security and Diplomacy, Segar became a Programme Manager for the International Energy Agency, 2008-15.