Founded in at least the 1940s as the Owen Sound Mohawks, the team was a member of the OHA Senior A league. The league was highly competitive and littered with teams that were constantly jumping back and forth from semi-pro. In the 1946-47 season, the Mohawks made it to the league final, but were put down by the Hamilton Tigers 3-games-to-2. In 1947, the team donned the Mercurys moniker. They made it back to the OHA Senior A final again in 1951 to beat a team from Sarnia 4-games-to-2. The Mercurys pushed on to the Allan Cup final where they faced the Fort Frances Canadians. The Canadians drove all the way from Fort Frances, Ontario on the Manitoba border to compete with the Mercurys at the Centennial Arena. The Mercurys won game one and the Canadians pulled even in game two. Game three went to the Mercurys and again the Canadians answered in game four. With the momentum, the Canadians broke the pattern and won game five to take their first series lead. The Mercurys had their backs to the wall, with one more loss the National Championship would go to Fort Frances. In game six, the Mercurys came out blazing and defeated the Canadians 7-4 to force a game seven. The seventh game was low scoring, but this played to Owen Sound's favour as they took the game 3-1, the series 4-games-to-3, and the Canadian Senior National Championship. The team's championship photo can be seen at the Bayshore Community Centre's Sports Hall of Fame. In 1952, the Mercurys made the finals again. Their opponents were the Stratford Indians. The defending Allan Cup champions were upset in full seven game battle, 4-games-to-3. A year later, the Mercurys made their third straight league final. Their opponents were the Kitchener-Waterloo Dutchmen. The Dutchmen took the series 4-games-to-2 and went on to win the Allan Cup as National Champions. The 1953-54 season saw the Mercurys push back to their fourth straight league final. In their way was the Stratford Indians. Unlike 1952, the Mercurys took it to the Indians and swept the series 4-games-to-none to win their second league title in four seasons. The Mercurys did not make it to the Allan Cup final in 1954, as the Eastern Championship went to the Northern Ontario Hockey Association's Sudbury Wolves. In 1956-57, the OHA Senior A league absorbed many teams from the Ottawa District Hockey Association. The Mercurys floundered in the eleven team league and finished last. The team folded and Senior hockey did not return to Owen Sound until 1969 with the Owen Sound Crescents. For the 2010-11 season, the Owen Sound Attack of the Ontario Hockey League wore the 1951 Mercurys jersey as a throwback third jersey in honour of the 50th anniversary of their 1951 Allan Cup victory.
