Conacher was one of the greatest pure athletes to play in the NHL. He won Canadian championships in football, lacrosse, wrestling and boxing in addition to the Stanley Cup.

"The Big Train" didn't start skating until he was 16 years old, but he more than made up for that late start by winning two Stanley Cup championships during his 12 seasons as an NHL defenseman and earning induction into the Hockey Hall of Fame.

At age 19, Conacher joined the Toronto Canoe Club of the Ontario Hockey Association in 1919-20 and led them to the Memorial Cup championship. The Toronto native continued to have success with amateur teams in the local area, and by the 1922-23 season the Toronto St. Patricks and Montreal Canadiens were trying to sign him to an NHL contract.

However, Conacher resisted their entreaties and accepted a scholarship to Bellefonte Academy in Pittsburgh. He was captain of the Pittsburgh Yellow Jackets when they won consecutive United States Amateur Hockey Association championships in 1924 and 1925.

Conacher signed with the expansion Pittsburgh Pirates, made his NHL debut on Nov. 26, 1925, and scored the first goal in team history that night in a 2-1 loss to the Boston Bruins. He had 13 points (nine goals, four assists) and finished ninth in voting for the Hart Trophy as the League's most valuable player.

Pittsburgh traded him to the New York Americans during the 1926-27 season, and in 1927-28 his 17 points tied Hap Day and Eddie Shore for the NHL lead among defenseman; his 11 goals tied Shore for first among defensemen.

After spending 1929-30 as player-coach of the Americans, Conacher was traded to the Montreal Maroons. In 1932-33 he was named to the NHL Second All-Star Team after finishing with a personal-best 28 points (seven goals, 21 assists) in 47 games.

With the Chicago Black Hawks in 1933-34 he had 23 points (nine goals, 14 assists) in 48 games, helping Chicago go from missing the playoffs in 1932-33 to winning the Stanley Cup for the first time in 1934. Conacher was named a First-Team NHL All-Star and finished second to Montreal Canadiens forward Aurel Joliat in Hart Trophy voting.

Conacher returned to the Maroons for the 1934-35 season and helped them to their final Stanley Cup championship that season.

In 1936-37, at age 35, Conacher was third among NHL defensemen with 25 points (six goals, 19 assists). He was named a Second-Team All-Star and was second in Hart Trophy voting to the Canadiens' Babe Siebert.

Conacher announced his retirement after the season, finishing his NHL career with 186 points (78 goals, 108 assists) in 498 games. He went into politics and won a seat in Canada's House of Commons in 1949, one that he held until he died on May 26, 1954.

He was named Canada's top athlete of the first half of the 20th century and was a charter member of the Canadian Sports Hall of Fame in 1955. Conacher won the Grey Cup, Canada's football championship, with the Toronto Argonauts in 1921, and is one of two people, along with Carl Voss, to have his name engraved on the Grey Cup and the Stanley Cup. He's been enshrined in the Canadian Football Hall of Fame (1963) and the Canadian Lacrosse Hall of Fame (1966), and the Lionel Conacher Award is given to Canada's male athlete of the year as voted by The Canadian Press.

Conacher was inducted into the Hockey Hall of Fame in 1994.