Ottawa—Vanier (formerly known as Ottawa East) is a federal electoral district in Ontario, Canada, that has been represented in the House of Commons of Canada since 1935. Previous to that date, it was part of the Ottawa electoral district that returned two members. The riding generally corresponds to the wards of Beacon Hill-Cyrville, Rideau-Rockcliffe and Rideau-Vanier. The riding became vacant because of the death of incumbent MP Mauril Bélanger on August 16, 2016. Mona Fortier was elected in the byelection to fill the seat on April 3, 2017.