Justin Fitzpatrick (born 21 November 1973) is an Irish former rugby union player. He played for London Irish, Castres Olympique, Dungannon RFC & Ulster. He had also held several coaching positions, including head coach of Dungannon RFC and the Seattle Saracens, and assistant coach of the United States national rugby union team.
He made his debut for the senior Ireland team in a 13–37 defeat against South Africa on 13 June 1998 going on to win 26 caps. Fitzpatrick was also a prominent member of the Ulster squad that was the first Irish team to win the 1998-99 Heineken Cup, defeating Colomiers 21–6 in the final before 49,500 fans at Lansdowne Road in Dublin. While a professional player at Ulster he helped Willie Anderson's Dungannon RFC side win Ulster's first All-Ireland League (AIL) title in 2001 beating favorites Cork Constitution in the Final. During Fitzpatrick's first season at Castres Olympique he helped the club win the Coupe de France in 2003 beating CS Bourgoin-Jallieu 27-26 in the Final. In the 2005/06 after returning from playing in France with Castres Olympique to help Mark McCall Ulster side win the Celtic League now the Pro12