Iain Mackay (born 24 April 1985) is a British field hockey player who competed at the 2012 Summer Olympics.
MacKay was educated at Bishop's Stortford College in Hertfordshire. Later, he attended college at Loughborough University.
He played junior hockey for Braintree Hockey Club and played senior club hockey with Reading in the Men's England Hockey League and began playing internationally in 2009 and helped England to a win in the 2009 Men's EuroHockey Nations Championship
He played in the 2010 Commonwealth Games in Delhi and was part of the silver medal winning England team that competed at the 2010 Men's Hockey Champions Trophy in Mönchengladbach, Germany.
He represented Great Britain at the 2012 Olympic Games in London in the field hockey tournament.
After the Olympics he left Reading to join Hampstead & Westminster.