While a local lawyer (he was appointed King's Council in 1947), Halter was heavily involved in the administration and organization of amateur sport in Winnipeg. From 1930 to 1945, he served as the president of the Winnipeg Amateur Athletic Association. His greatest contributions to sport, however, came in football. He began his association with the Winnipeg Rugby Football Club in the mid-1930s and at different times served as the club's treasurer and president. While the championship football teams from eastern and western Canada had been meeting for the Grey Cup since 1921, by the 1950s there were still two different leagues that had over the years disagreed over rules of play and the incorporation of professional players. In 1952, Halter was named deputy commissioner of the Western Interprovincial Football Union, and a year later he became commissioner. In 1956, he played a key role in the amalgamation of the WIFU and eastern "Big Four" into a federation known as the Canadian Football Council. Halter was the registrar of the CFC and retained the commissionership of the WIFU. Two years later, however, in 1958, this union was formalized with the creation of the Canadian Football League. Halter was named the league's first commissioner. It was not only in football that Halter made significant contributions to Canadian sport. While he was involved with the Winnipeg Rugby Football Club, he was also influential within both the provincial and national amateur sport governing bodies. This is not surprising given that rugby football was still governed by the amateur code at the time, so Halter's efforts with football would have fit within the larger project of amateur sport. He was president of Manitoba's branch of the Amateur Athletic Union of Canada,the national governing body of amateur sport-between 1935 and 1938, at which time he was named the president of the national AAU, a position he held until 1946. Upon retiring from the CFL, Halter continued to contribute to the administration of sport in his home province. From 1965 to 1971, and again from 1978 to 1981, he was the chairman of the Manitoba Horse Racing Commission. For his varied and considerable contributions to Canadian sport, Sydney Halter has been widely recognized. He is a member of the Canadian Football, Canadian Horse Racing, Canadian Olympic, and Manitoba Sports Halls of Fame. Halter was named an officer of the Order of Canada in 1977.