De Glanville played for Durham University while an Economics student, then at Oxford University won a Blue with Oxford University RFC and also represented England U21s. de Glanville joined Bath in 1989 and captained them to a league and cup double in 1996, partnering Jeremy Guscott in the centre for this club that season, as well as many others. He played 189 times for Bath over a 12-year career, scoring 53 tries. He started for Bath in the victorious 1998 Heineken Cup Final as they defeated Brive. He made his England debut as a replacement in the match against the Springboks in 1992. Many of De Glanville's international caps were earned in a replacement role, as the incumbent centres were Will Carling and Jeremy Guscott. De Glanville is seen as likely to have won many more caps if it weren't for this firmly entrenched Carling-Guscott combination, a pairing solidified by early Carling-Guscott successes like the 1991 Rugby World Cup. In the Autumn of 1996 coach Jack Rowell appointed him as England captain following Will Carling's decision to step-down, following Englands 1996 Five Nations Championship win. However, there was criticism of his inclusion in the starting XV for the 1997 Five Nations as it wasn't felt that he was a good enough player to be guaranteed a place in the team. He was not selected for that summer's Lions tour to South Africa losing his place to uncapped Will Greenwood. Under new coach Clive Woodward in autumn 1997 he lost both the captaincy to Lawrence Dallaglio and his starting position to Greenwood, though he remained a useful squad member. He showed some good form in the 1999 world cup, particularly in the pool game against New Zealand. In total he won 38 caps for England and started in the centre throughout the 1994/1995 season, including an outstanding performance in the first tour to South Africa after apartheid, where he played in both test matches.
After rugby
Chiding his renowned good-looks, teammates often referred to De Glanville as "Hollywood"; a trait seemingly incongruous with his hard, committed playing style. In 2003 he competed in the BBC's Superstarstelevision show, winning the kayaking and golf events but eventually coming last in the final. He is a regional member of Sport England and from 2012 is the Director of Elite Sport at Hartpury College. De Glanville lives in Bath, UK.