Career
He played club rugby for Leeds Tykes (now Leeds Carnegie), the defunct Border Reivers, Edinburgh and Sale Sharks. He played both sides of the scrum. He debuted for Scotland in the February 2003 game against Ireland but became a regular starter for Scotland after his solid performance against New Zealand in the Autumn Test series, replacing Tom Smith after his retirement.
In April 2009 it was announced that Kerr will play for English club Sale Sharks in the Guinness Premiership.
He signed a two-year deal keeping him at the Stockport based club for the 2009/10 and 2010/11 seasons. On 18 August 2010, Kerr announced he would retire from rugby due to a neck injury.
Kerr currently works as a Chartered Building Surveyor.