Born in Winnipeg, Ken Reardon first excelled as a youngster in the game of hockey. He won the city playground championship with Clifton Community Club in 1931 and 1932. He helped the East Kildonan Bisons capture the Bantam Championship in 1933 and 1934 and also helped the Bisons win the Midget City crown in 1935. The following year he won the Juvenile City Championship with the Winnipeg Monarchs.
After two more seasons with the Blue River Rebels of the B.C. Junior League, Reardon joined the Edmonton Roamers in 1938-39 and was a Memorial Cup finalist that year. For the 1940-41 season, he signed with the Montreal Canadiens and played two seasons. He won the Allan Cup with the Ottawa Commandos in 1942-43. War interrupted his professional hockey career. Reardon won the Field Marshall Montgomery Award of Merit and he spent two years with the Canadian Armed Forces team during World War Two.
He returned to Montreal in 1945 and won the Stanley Cup. He was named NHL second team All-Star in 1945-46. Over the next 4 seasons he was first team All-Star twice and second team All-Star one more time. During his playing career Reardon played in 341 regular games (26 goals, 96 assists, 122 points and 604 penalty minutes) and 31 playoff games (2 goals, 5 assists, 7 points and 62 penalty minutes). After his retirement in 1950, he remained with Montreal as their Director of Public Relations, became the assistant general manager in 1956 and 4 years later was made the team's vice-president. He held that position until 1965.
Ken Reardon was also inducted into the Hockey Hall of Fame in 1966, and the Manitoba Hockey Hall of Fame.