Fitzpatrick joined London Irish at the age of 16, and played for their first team from 1994.[1] Born in Chichester, West Sussex, England, he qualified for Ireland through his mother, and he was selected for Ireland's 1998 tour of South Africa,[2] making his debut in a 13–37 defeat against the Springboks on 13 June 1998. He went on to win 26 caps.[3]
In 2003, after making 73 appearances for Ulster, he moved to Castres Olympique,[8] and in his first season there he helped the club win the Coupe de France, beating CS Bourgoin-Jallieu 27-26 in the final.[9] He returned to Ulster in 2005.[10] He was forced to retire through injury in 2010.[2]
In 2013 he became head coach of Seattle Saracens then known as Seattle OPSB.[15] During his first spring season, Fitzpatrick guided the club to USA Rugby Elite Cup semifinal and a USA Rugby Division 1 final in XV's, and assisted Waisale Serevi and Ben Gollings guide the club to win the National 7's title. Soon after arriving in Seattle, he was appointed forwards coach for the Collegiate All-Americans, and in October 2013 he became assistant coach for the U.S. national rugby team, spending three years in the position[2] and helping the team qualify, prepare and compete in the 2015 Rugby World Cup.[16]
In Spring 2017, he was recruited by the Houston SaberCats to become their Head Coach and build Houston’s first professional rugby team to compete in the inaugural season of Major League Rugby. He left the position on 2 May 2019.[17]