In 1983 Dunn began his 1st Grade Career in the NSWRL premiership with Sydney's Eastern Suburbs club, where he played for two years before moving to the Canterbury-Bankstown Bulldogs, his most successful club where he played 100 games over 5 years. At the end of the 1986 NSWRL season, he went on the 1986 Kangaroo tour of Great Britain and France. A major player and staff change at Canterbury prompted a move to the Penrith Panthers where Dunn spent 2 years before moving to the Parramatta Eels his most unsuccessful club where he retired at the end of 1995 before returning for one year to his first club, the newly re-branded Sydney City Roosters. In New South Wales Rugby League season 1988 Dunn was the recipient of the Clive Churchill Medal for his man-of-the-match performance at in the Grand Final-winning Canterbury team. Dunn also played for the Penrith Panthers, winning another premiership with them in NSWRL season 1991. Following the grand final victory he travelled with the Panthers to England for the 1991 World Club Challenge which was lost to Wigan. He also played for the Sydney Roosters and Parramatta Eels clubs. Dunn also played in the City 1sts side in 1985 and 86, and the City Origin side in 87 and 90, this was because he played his last year of junior football for Bondi United, a Sydney-based club. He also played in the Country Origin sides of 1988, 89 and 91 because of his country based roots. Dunn was unlucky not to play more Origin than one game in 1988 two games in 1989 because he was unfortunately in the same era as forwards like Steve 'Blocker' Roach, David 'Cement' Gillespie, Paul 'Chief' Harrigan, Paul 'Siro' Sironen and John Cartright.
Post-playing career
In 2000 he was awarded the Australian Sports Medal for his contribution to Australia's international standing in rugby league. Appointed the Chief Executive of the re-instituted South Sydney Rabbitohs, Dunn departed after the club’s disappointing return season of 2002 due to unrest in the club. In 2008, Dunn was appointed to the board of the Cantebury-Bankstown Bulldogs Football club. In the following year the 'Boys from Belmore' made it to the preliminary finals and only missed out on the Minor Premiership because of a controversial Video Referee decision and being stripped of 2 points for an interchange mixup, and then in 2010 was made Deputy Chairman of the club.
