The Michigan Central Railway Tunnel is a railroad tunnel under the Detroit River connecting Detroit, Michigan, in the United States with Windsor, Ontario, in Canada. The U.S. entrance is south of Porter and Vermont streets near Rosa Parks Boulevard. The Canadian entrance is south of Wyandotte Street West between Cameron and Wellington Avenues. It was built by the Detroit River Tunnel Company for the Canada Southern Railway, leased by the Michigan Central Railroad and owned by the New York Central Railroad. The tunnel opened in 1910 and is still in use today by the Canadian Pacific Railway.

The Detroit River flows west and south for 24 nautical miles from Lake St. Clair to Lake Erie as a strait in the Great Lakes system. The river divides the metropolitan areas of Detroit, Michigan, and Windsor, Ontario—an area collectively referred to as Detroit–Windsor—and forms part of the border between Canada and the United States. The Ambassador Bridge, the Detroit–Windsor Tunnel, and the Michigan Central Railway Tunnel connect the cities.