Primeau played all nine of his NHL seasons with the Toronto Maple Leafs and his clean but still hard-nosed play earned him the nickname "Gentleman Joe." Although he was born in Lindsay, Ontario, and raised in Victoria, British Columbia, he moved to Toronto at an early age, where he played with St. Michael's College in a four-team prep school league that included Upper Canada College, University of Toronto Schools and St. Andrew's.
In 1924 he moved on to the Toronto St. Mary's team and his play impressed Frank Selke - who was running the Toronto Ravinas of the Can-Pro league - who arranged for him to play with the senior Marlboros in 1926-27. From there he was assigned to play for the Ravinas and his exploits - a league-leading 26 goals in 41 games - earned him a two-game tryout with the Maple Leafs. Primeau spent most of 1928-29 with the Can-Pro league's London Panthers, but he was recalled by the Leafs for the last six games of the season.
During the 1929-30 season, Primeau's pro career finally took flight when Leafs coach Conn Smythe put the 23-year-old centre on a line with a pair of 18-year-old rookies, Charlie Conacher and Harvey "Busher" Jackson. The Kid Line was born. The three young players - all superstars, Stanley Cup winners and Hall of Famers in the making - complemented each other's style perfectly.
A testament to Primeau's playmaking ability was the fact that Jackson won a scoring title while Conacher twice led the league. But as Primeau revealed, it was chemistry as much as talent that made the line work. In 1931 the Leafs moved into a new rink, leaving the Mutual Street Arena for the palatial Maple Leaf Gardens. That first season, the team won the Stanley Cup, led by the incomparable Kid Line.
Throughout his playing days, Primeau was also involved in business, and his early retirement from the game in 1936, when he was just 30 years old, was directly attributable to just that. It was first called Joe Primeau Block but soon amalgamated to form Primeau-Argo Block and expanded to include five plants across the country.
Once he had established the business, his interest in returning to the rink grew further and further away. During his playing days, in 1932, Primeau had coached the West Toronto Juniors, and he continued to work behind the bench for local teams right through the war - most notably a six-year stint with the Upper Canada College team. In 1944-45, he returned to St. Mike's as coach and won the coveted Memorial Cup in his first season. He then coached the RCAF team stationed in Toronto, and after he was discharged he hooked up with the Marlboro seniors, whom he led to the Allan Cup championship in 1949. In 1950-51, he became coach of the Maple Leafs and won a Stanley Cup in his first year. Thus he became - and remains - the only man to coach teams to the Allan, Memorial and Stanley cups.