Port Dalhousie is a community in St. Catharines, Ontario, Canada. Known for its waterfront appeal, it is home to the Royal Canadian Henley Regatta and is historically significant as the terminus for the first three routes of the Welland Canal, built in 1820, 1845 and 1889.

St. Catharines is the most populous city in Canada's Niagara Region, the eighth largest urban area in the province of Ontario. As of 2017, St. Catharines has an area of 96.13 square kilometres (37.12 sq mi) and 140,370 residents. It lies in Southern Ontario, 51 kilometres (32 mi) south of Toronto across Lake Ontario, and is 19 kilometres (12 mi) inland from the international boundary with the United States along the Niagara River. It is the northern entrance of the Welland Canal. Residents of St. Catharines are known as St. Catharinites. St. Catharines carries the official nickname "The Garden City" due to its 1,000 acres (4 km2) of parks, gardens, and trails.