Albert Samuel "Alby" Mathewson (born 13 December 1985 in Hastings, New Zealand) is a rugby union player for the Western Force in Super Rugby. He plays as a scrum-half. He has played four Test matches for the All Blacks.
Mathewson was born in Hastings, New Zealand. He studied at Victoria University after finishing his schooling at Hastings Boys' High School. He made his Wellington debut in 2006 and Hurricanes debut in 2007, before shifting to the Blues in 2010. Mathewson made his international debut for New Zealand in 2010.
In 2012 Mathewson signed a two-year contract with the Western Force in Australia, which he extended until 2016 two years later.