MacMillan, a native of Charlottetown, PEI spent parts of seven seasons in the National Hockey League with the Toronto Maple Leafs, Atlanta Flames and New York Islanders, recording 151 points (74 goals, 77 assists) and 184 penalty minutes in 446 career games. He went on to add 12 points in 53 Stanley Cup Playoff games.
Following his playing career, MacMillan turned his attention to coaching and in his first season behind an NHL bench as an assistant in 1979-80, he helped the New York Islanders win their first Stanley Cup in franchise history. MacMillan went on to become the head coach for the Colorado Rockies the following season. In 1982 when the Rockies relocated to New Jersey, MacMillan was named the first head coach in Devils history, spending two seasons with the team.
Our thoughts are with MacMillan's family and friends at this difficult time.