David Trent Johnston (born 29 April 1974) is an Irish-Australian cricket coach and former player. He was born in Wollongong, New South Wales, and played his early cricket for New South Wales in Australian domestic competitions. A right-handed batsman and right-arm fast-medium bowler, he later moved to Ireland, and made his debut for the Ireland cricket team in 2004. Johnston was subsequently named captain of Ireland, and was a regular fixture in the national team until his retirement in 2013.