One of the most recognizable names in Welsh football, Kellaway started his career with Aberystwyth making his debut in 2003. His first stint at Park Avenue lasted seven years in which he made 114 league appearances, scoring 24 goals. He was also named in the Cymru Premier Team of the Season in his last season of his first stint.

Kellaway made the move down under in 2010, joining Australian side Dandedong Thunder alongside former Rooster and then Aberystwyth teammate Luke Sherbon. He made 6 league appearances and scored a singular goal for the NPL Victoria club before being picked up by A-League side Melbourne Victory on a three-month injury replacement contract.

Geoff made his A-League debut in a 2-2 draw to North Queensland Fury, coming on as a substitute becoming the 500th player to play in the A-League. He was released by Melbourne at the end of his contract after playing 8 league games and returned to Wales in 2011.

Following his return to the UK, Geoff returned to Aberystwyth making 27 league appearances and scoring 8 goals in the 2011/12 season before leaving the club again to join Llanelli.

During his short spell at Stebonheath Park he made 16 league appearances and scored 1 goal before leaving after the club folded in 2013. He then moved to Carmarthen Town for a short spell where he made 11 league appearances scoring 3 goals. He then returned to Aberystwyth in 2013 where he spent a further eight years, where he played 182 times in the league, scoring 44 goals. He left Aberystwyth once again at the end of the 2020/21 season and he joined the Roosters for 2021/22.

He scored 14 goals in 31 games in the 2021/22, finishing as the club’s top scorer!