Grantley began his television acting career in 2003, starring in Fat Cow Motel. Over the next two years, he had small guest roles in Marking Time, Small Claims and The Cooks. In the summer of 2005 / 2006, he had a role in the short lived series headLand. In 2006, he had a small role in Foxtel's Supernova series and in 2007, had a 10-episode guest role in Home and Away.