Born in Newcastle, New South Wales, Anderson played his junior football for the West Maitland Reddogs and Kurri Kurri Bulldogs before being signed by the Newcastle Knights. He played for the Knights' NYC team in 2011. At the end of the 2011 season, Anderson was named the Knights' NYC Player of the Year and the Players Player of the Year.
In October 2011, Anderson was forced to decide on whether to sign with the Penrith Panthers or re-sign with the Knights. Phil Gould, the coaching director of the Panthers, offered an easier path to first-grade football with the loss of prop Petero Civoniceva. However, Wayne Bennett, the coach of the Knights, personally told Anderson that he was in his future plans for the Knights.
On 21 October 2011, Anderson re-signed with the Knights on a 1-year contract.
In September 2012, Anderson signed a 1-year contract with the Penrith Panthers starting in 2013 after failing to make first-grade with the Knights in 2012.
On 22 September 2013, Anderson was named on the interchange bench in the 2013 New South Wales Cup Team of the Year. In October Sam was also named as the Panthers New South Wales Cup Player of the Year, so capped off a very successful 2013. 
On 9 July 2014, Anderson again played for the New South Wales Residents against the Queensland Residents.
On 3 May 2015, Anderson played for the New South Wales Residents against the Queensland Residents for the third year in a row. He added another NRL game to his tally and captained the Panthers' New South Wales Cup team.