The brothers were all educated at Newington College (1984–1991),[2] and took up rowing coached by Olympian and fellow Old Newingtonian Michael Morgan and deputy headmaster Robert Buntine.

Stewart's first state representative selection for New South Wales came in 2001 in the men's senior eight who contested the King's Cup at the Interstate Regatta within the Australian Rowing Championships[3] From 2001 to 2004 and in 2008 he rowed in New South Wales men's senior eights competing for the King's Cup at the Interstate Regatta.

[4] Stewart made his Australian representative debut in 1995 aged eighteen, competing at the World Rowing U23 Championships in Groningen in the men's eight who finished in eighth place.

[5] His next representative appearance was in 2000 and again at the World Rowing U23 Championships in a coxless four which won the silver medal.

[5] In time for the 2004 Athens Stephen was back in the stroke seat of the Australian men's eight with his brothers Geoff and James at four and five.