The Denver Nuggets’ Carmelo Anthony, left, receives instructions from assistant coach John MacLeod in 2003. (Kevin Rivoli/AP)

John MacLeod, the longtime NBA coach who led the Phoenix Suns to the 1976 NBA Finals, died April 14. He was 81.

The death was confirmed by his son, Matt MacLeod. The elder MacLeod had fought Alzheimer’s disease for more than a decade. Additional details were not immediately available.

Mr. MacLeod is the winningest coach in Suns history, going ­579-543 in the regular season from 1973-87. He also coached the Dallas Mavericks from 1987 to ’89 and the New York Knicks in the ­1990-91 season, finishing his ­18-year head-coaching career with a 707-657 mark.

Mr. MacLeod had his most success in Phoenix, capped by the 1975-76 “Sundarella Suns” run to the NBA Finals. The Suns lost to Boston in six games in the finals, with the Celtics’ triple-overtime victory in Game 5 at Boston Garden regarded as one of the greatest games ever.

“His passion for the game was matched only by his endearing personality, humility and class, a man who was loved by everyone that had the pleasure of interacting with him,” the Suns said in a statement. “Coach MacLeod was a winner in every sense and will be dearly missed.”

His Phoenix teams made nine playoff appearances, also reaching the Western Conference finals in 1979 and 1984. He had a ­franchise-record 37 playoff victories and was placed in the Phoenix Suns Ring of Honor in 2012.

Mr. MacLeod in 1999. (Matt York/AP)

John Matthew MacLeod was born in New Albany, Ind., on Oct. 3, 1937. He starred at Providence High School in nearby Clarksville and played college basketball at Bellarmine University in Louisville, just across the state line.

Mr. MacLeod led the Mavericks to Game 7 of the Western Conference finals in his first season with the team and worked as an assistant with Phoenix, Denver and Golden State, ending his coaching career with the Warriors in 2006. He was a college head coach at Oklahoma from 1967 to 1973 and at Notre Dame from 1991 to ’99. His son was a member of the Fighting Irish squad in Mr. Mac­Leod’s last two seasons.

In addition to his son, survivors include his wife, Carol, and daughter, Kathleen.