Allan MacInnis is a Canadian former professional ice hockey defenceman who played 23 seasons in the National Hockey League (NHL) for the Calgary Flames (1981–1994) and St. Louis Blues (1994–2004). A first round selection of the Flames in the 1981 NHL Entry Draft, he went on to become a 12-time All-Star. He was named the Conn Smythe Trophy winner as the most valuable player of the playoffs in 1989 after leading the Flames to the Stanley Cup championship. He was voted the winner of the James Norris Memorial Trophy in 1999 as the top defenceman in the league while a member of the Blues. In 2017, MacInnis was named one of the '100 Greatest NHL Players' in history.

Defence or defense in ice hockey is a player position that is primarily responsible for preventing the opposing team from scoring. They are often referred to as defencemen, D, D-men or blueliners. They were once called cover-point.