Cap-des-Rosiers Lighthouse, National historic lighthouse in Gaspé, Canada.

Cap-des-Rosiers Lighthouse is a 34.1-metre stone tower faced with firebrick, standing on a steep cliff on the south shore of the Saint Lawrence River where it meets the Gulf of St. Lawrence. Its walls are over seven feet thick at the base and taper to three feet at the top, with foundations extending eight feet below the surface. A powerful light 136 feet above high water served as a major coastal aid for ships entering the estuary.

The lighthouse was built between 1854 and 1858 by the Department of Public Works, part of a series of tall tapering towers raised on the Gulf of St. Lawrence and Lake Huron; the plaque at its base dates it to 1858. During the Second World War, on 15 September 1942, keeper Joseph Ferguson spotted a German U-boat and sounded the civil defence alarm. It was designated a national historic site on 11 June 1973.

The lighthouse is run by the non-profit organization Site historique maritime du Phare de Cap-des-Rosiers, which manages the site and gives visitors access. A plaque installed by the Historic Sites and Monuments Board of Canada in 1977 stands at the base of the tower, inscribed in French and English.

The site opens to visitors during the summer season with guided tours available most days, giving a chance to explore the tower and its interior. Bring a jacket since winds from the Gulf can be strong and temperatures stay cool even in summer months.

On 15 September 1942, keeper Joseph Ferguson spotted a German U-boat from the tower and sounded the civil defence alarm. The lighthouse was built between 1854 and 1858, and its stone tower faced with firebrick has walls over seven feet thick at the base, tapering to three feet at the top.