Sydney Grange began his career as assistant registrar of the New South Wales Amateur Swimming Association, a post which sometimes involved rowing a dinghy for the diving judges at the tidal Abbotsford Baths. Grange went on to become the honorary secretary and treasurer of the NSW Olympic Council from 1948 to 1972.

Between 1959 and 1985 he was a member of the National Executive Board of the Australian Olympic Federation and vice president between 1972 and 1977. From 1977 until his retirement in 1983, he was president. Upon retirement he became honorary life president.

Grange was vice president of the Australian Swimming Union between 1963 and 1968 and was then honorary director until 1979. He went on to become a member of the Executive Board for the International Swimming Federation between 1964 and 1984, vice president from 1972.

He served on the Australian Commonwealth Games Association Executive Board from 1969 until 1980.

Grange was Sectional Manager (Swimming) for the Australian Olympic team at the 1952 Helsinki Games, General Manager and Chef de Mission for the 1960 Rome Games, and Director of Administration for the 1964 Tokyo Games and the 1968 Mexico Games. He was also a member of the Organising Committee for the 1956 Melbourne Games.

He was made a life member of the NSW Amateur Swimming Association in 1956, and the Australian Swimming Union in 1976. He was made a life member of the NSW Olympic Council in 1960, the Australian Olympic Federation in 1978, and the Australian Commonwealth Games Association in 1980. He was awarded the Silver Medal of the Olympic Order in 1980. He radiated dignity, and a cautious wisdom.

Grange became an Officer of the Order of the British Empire (OBE) in 1957 and became an Officer of the Order of Australia (AO) in 1984 for his service to amateur sport. In 1970 he became a Member of the Fifth Class of the Royal Victorian Order (MVO).