Richard Stagg was born on 27 September 955, the son of Walter and Elise Patricia Stagg. He was educated at Winchester College, then Oriel College, University of Oxford. In 1982, he married Arabella Clare Faber, having three sons and two daughters.

Stagg joined the Diplomatic Service in 1977 and his diplomatic career included: Foreign and Commonwealth Office, 1977–79; Sofia, 1979–82; The Hague [the Netherlands], 1982–85; FCO, 1985–86; UK Representaion to EC, Brussels, 1987–88; Soviet Department, FCO, 1988–91; UK Representation to EC, Brussels, 1991–93; Private Secretary to Foreign Secretary [Douglas Hurd], 1993–96; Head, EU (External) Department, FCO, 1996–98; Ambassador to Bulgaria, 1998–2001; Director of Information, 2001–03, Director General (Corporate Affairs), 2003–07, FCO; High Commissioner to India, 2007–11; Ambassador to Afghanistan, 2012–15.