[3] Clapham spent most of his senior footballing career with ISPS Handa Premiership club Canterbury United FC.

Clapham has long been considered one of the top players in the New Zealand Football Championship, being named to the league's team of the month in November, December, January, and February during the 2009–10 season.

[5] Clapham has earned national representation at Under-20 level, where he represented New Zealand at the 2007 FIFA U-20 World Cup in Canada.

[6] After impressing for Canterbury United during the 2009–10 season, Clapham was selected as a part of a 15-man FIFA World Cup training camp for Australia and New Zealand-based players.

[8] Clapham made his official international debut on 10 October 2010 when he came on as a late substitute in his country's 1–1 draw with Honduras.