The Regional Municipality of Niagara (2001 population 410,574), also known as Niagara Region, or (colloquially) Regional Niagara, is a regional municipality comprising 12 municipalities located in southern Ontario in Canada.

The region occupies most of the Niagara Peninsula. Its eastern boundary is the Niagara River, which is also the border with the United States. It is bounded on the north by Lake Ontario and on the south by Lake Erie. The most important agricultural enterprise in Niagara is viticulture, or wine-growing. Canadian wines outscored the very best French wine at the historic St. Catharines Wine Tasting of 2005. The region's Wine Country is one of the major tourist attractions, along with the Shaw Festival and the internationally-renowned Niagara Falls.