Dunfield and his wife Sonya helped coach Manley to three Canadian national titles and silver medals at the 1988 Olympics and Worlds. The couple had been living in Seattle and Peter Dunfield had recently developed heart and lung problems.
Manley announced news of his death through Twitter, writing: "My heart is empty tonight with the passing of my coach Peter Dunfield. You will be in my heart. Thank you for everything you taught me in life."
While coaching in Ottawa, Dunfield was based out of the Gloucester Skating Club.
Skate Canada's Emery Leger coached alongside Dunfield in the early 90s and said he was a perfectionist.
"Detailed. Focused. Very Disciplined. Strict. He knew exactly what he wanted," said Leger.
Both Peter and Sonya Dunfield were elected to Skate Canada's Hall of Fame as builders in 2001.
Prior to coaching, Dunfield was a competitive skater. He was the 1951 junior national champion and the senior bronze medallist in 1952 and 1953, and also represented Canada on two World and North American championship teams.
His wife Sonya was a medallist at two World Championships and represented the United States at the 1952 Olympic Games.
"Their whole life was figure skating," said Leger. "They were really, what we call 'royals' in the skating family."
Dunfield is survived by his wife and two sons.