While at school he played for the
Amersham and Chiltern Rugby Football Club and also
Fullerians RFC as a pupil of Watford Grammar Boys’ Grammar School. He first played for
Wasps at eighteen in their Colts side, before being selected for their senior team. In that season he made his first appearance for England, in the U19s against Italy. During his time at university, Lewsey combined his studies with playing professionally for
Bristol RFC. He then rejoined
London Wasps at the age of twenty one after completing his degree. He won his first full England caps in 1998 against New Zealand and then South Africa. In the following years, he was a member of the successful Wasps side that won 12 trophies, starting with the Tetley's Bitter Cup in 1999, in the final of which he scored a try. The following year Wasps retained the cup, and in the 2000 final he again scored a try this time against Northampton, having spent the morning at Sandhurst with his platoon on routine room inspection, block cleaning and parade drill. Amongst his 12 trophies at Wasps were four
Premiership titles in 2003, 2004, 2005 and 2008. Lewsey played in all four finals, and scored two tries in the 2003 final and one in the 2008 final. He also played in the victorious 2004 and 2007 Heineken Cup finals. After a good run of form with the national team, he scored 11 tries at the 2007
Middlesex 7s to help Wasps win their first
Middlesex 7s title since 1993. He became the tournament's top try and points scorer. On 5 April 2009, Lewsey announced that he would retire from Rugby at the end of the 2008/09 season. That year with Wasps he won Player of the Year, but was not selected for the 2009 British & Irish Lions team for the tour to South Africa.
International Lewsey appeared for England in all three tests in the 2001 North American tour, and was a member of the
England side that won the
Hong Kong Sevens in 2002. He also represented England in
sevens at the
2002 Commonwealth Games, opting to play in the tournament over touring Argentina with the National team. Lewsey made his England home debut in the
Six Nations Championship in 2003 after an injury to
Jason Robinson. He scored twice in a 40–5 win over Italy. He followed this with the opening try in his next game against Scotland, and was part of the Grand Slam winning side. He had a key part in the tests against
New Zealand and
Australia on the June 2003 Southern-hemisphere tour. By then he was first-choice
full-back, Robinson having moved to
wing. He was a part of the
2003 World Cup winning squad, and scored five tries in the 111–13 defeat of
Uruguay. He was selected for the
2005 British & Irish Lions tour to New Zealand. He made an ideal start scoring two tries in the first five minutes against
Bay of Plenty. Lewsey was widely viewed as a standout player for the Lions, despite the team's poor results. Lewsey continued to be an integral part of the England team at the 2006 Six Nations. Lewsey featured heavily in England's campaign to retain the Rugby World Cup in 2007, playing in every game en route to the final. He scored the only try against France in the 14–9 victory which put England into the last two. However, just before half-time in the same match he picked up a hamstring injury which ruled him out of the final. That semi final was to be his last game for England. England's coach
Brian Ashton did not select Lewsey for the England squad to compete in the
2008 Six Nations squad. However, he was called up for
Martin Johnson's England Squad for 2008/2009, but was not selected to play. On 10 December 2008 Lewsey announced his retirement from international rugby to concentrate on his club career, ending his time in the England set-up, which spanned more than 10 years and claiming 55 caps with 22 tries scored. Due to his parentage Lewsey also qualified to play for
Wales but chose to represent England as he had received a call-up from them first. His mother is from the
Swansea Valley area while his father is half Welsh. ==Post rugby career==