In September 2006, Gareth Matthews joined Norwich City from the renowned Cherry Orchard Boys Club in Dublin. He had an impressive Milk Cup tournament in the summer of 2005. In January 2006 he was Man of the Match as he captained the Dublin District Schoolboys League to victory over Glasgow Celtic in a challenge match at Home Farm FC, Whitehall, Dublin.

Following his fine performance here was selected to play for the Republic of Ireland's U16's against Israel in February. City scout Karl Brady then watched him play against Northern Ireland in March this year at Dundalk FC and again impressed. Having trialled with Norwich over the summer of 2006, when Gareth returned from representing the Republic of Ireland in a tournament in Hungary at U17 level, the club offered him a two year scholarship.

Gareth is predominantly a right back but such is his versatility, he can adapt to play anywhere across the backline. He is a quick and tenacious defender who contributes well in attack with excellent distribution and crossing.

He was recently described by the Republic of Ireland youth coach Sean McCaffrey as "a good defender, good on one vs ones, supports the attack well and has already scored two goals for the Under-17s, against Italy and against Azerbaijan. Matthews is a good solid player. We definitely think he has a future and he has a very good attitude as well."

Gareth cut short his second year at Norwich at returned home to Ireland in February 2008, signing for UCD.

Matthews parted company with UCD at the end of the 2010 after making 17 appearances for the club. On 21st February 2011, Matthews joined Shelbourne for the 2011 First Division season. He made 30 appearances for Shelbourne in his first season.