Sullivan played in the NHL All-Star game five times (1955, 1956, 1958, 1959, 1960) and was named the New York Rangers captain for the 1957-58 season.

Sullivan was severely injured, and very nearly killed, on November 26, 1956, when defenceman Doug Harvey of the Montreal Canadiens speared him in the stomach, rupturing his spleen, where a Catholic priest was even brought to the hospital to deliver his last rites, however Sullivan survived and resumed his career with the New York Rangers.

[2] Sullivan became the head coach of the Rangers during the 1962–63 season when fans began to demand Muzz Patrick resign.

He was dismissed on March 31, 1969 after two consecutive seasons of the Penguins failing to qualify for the playoffs due to a pair of fifth-place finishes.

[3] During the 1974-1975 NHL season, Sullivan replaced Jim Anderson as head coach of the expansion Washington Capitals.