Born in Moruya, New South Wales, Weyman played his junior football for the Moruya Sharks. While attending Carroll College in 2001 and Erindale College in 2002, Weyman was selected for the Australian Schoolboys team and was captain of the team.[3][4] In 2002 and 2003, Weyman was selected for the Junior Kangaroos team and played for the New South Wales U19s in 2003.
In May 2008, Weyman signed a two-year deal with the St. George Illawarra Dragons starting in 2009, despite being offered a one-year extension with the Raiders.[6][7]
In 2008, Weyman was suspended for six weeks after punching Gold Coast Titans forward Daniel Conn, breaking Conn's nose and leading the media to brand Weyman as a "thug".[6][8] The incident was the low-point of Weyman's 2008 season and he played only seven NRL matches for Canberra that year.[6]
In 2009, Weyman was selected for Country in the City vs Country Origin match on 8 May 2009.[9] Later that month Weyman was named in the 17-man squad to represent New South Wales in the opening game of the 2009 State of Origin series.[10] Weyman made his Origin debut on 3 June 2009, in Melbourne at Etihad Stadium. Weyman missed the final game of the Origin series with an ankle injury.
In 2012, Weyman tore his anterior cruciate ligament in his right knee and had to have reconstructive surgery.[12] He was ruled out for the rest of the 2012 NRL season having only played 10 games.
Super League
In July 2013, Weyman signed a two-year deal with Hull Kingston Rovers for the 2014 Super League season. During the 2014 season, he scored four tries in four consecutive games which placed him 2nd in the Hull Kingston Rovers try charts for a brief period of time.[13] Weyman retired in March 2015.