Thomas Joseph Mahony (1880-1961) emigrated from Ireland to Canada as the youngest of ten children. He would grow up to be a member of city council, and the managing director of the Ontario Good Roads Association. Nicknamed "Mr. Good Roads" for his work in promoting the building and repair of roads everywhere, he was named 1954 Man of the Year by the International Road Federation.
Although generally a model citizen, Mahony came under fire in the summer of 1925, when a piece of land he owned with Hugh Bertram in Saltfleet Township was offered for sale to the city council for a park. The Parks Board had promised Mahony and Bertram to buy the land from them. However, when it came time to pay them, the city council voted against the land purchase. Apparently many councillors and citizens thought that the land was too far from the center of town to be useful as a park. Many also thought it was too expensive at $25,000 for 183 acres, or $137/acre. Mahony, Bertram and even the Parks Board claimed that the City Council had broken their promise to pay. However, when they still did not change their mind by November 1925, Mahony and Bertram withdrew their offer. The City did buy the land four years later for $20,000.
In 1945, on the suggestion of T. B. McQuesten three leaders of the British empire were honoured, when Hamilton parks were named after them. Mahony Park was renamed Crerar Park after General Henry Duncan Graham Crerar (1888-1965), a celebrated officer from World War II born in Hamilton. The two other leaders honoured were Sir Winston Churchill and Field Marshal Viscount Montgomery of Alamein. However, almost 40 years later local residents asked that the park's name be changed back to Mahony Park. This official name change was approved April 12, 1983.