Thomas John Mitchell Ashley ONZM (born 11 February 1984 in Auckland) is a sailor from New Zealand, who won the gold medal in the men's sailboard event at the 2008 Summer Olympics, he also won the 2008 RS:X World Championships.

Ashley attended Westlake Boys High School in Auckland, which had earlier fostered the development of other notable sailors, including Chris Dickson and Dean Barker.

Before the start of the medal race Ashley was in first position, only one point in front of Casper Bouman from the Netherlands.

Both sailors then had the same points (23), but Bouman was crowned as the World champion thanks to his better position during the medal race.

In the 2009 New Year Honours, Ashley was appointed an Officer of the New Zealand Order of Merit, for services to board sailing.