Desmarais is a French surname, associated especially but not exclusively with a powerful business and political family in Canada. Notable people with the surname include:
André Desmarais (born 1956), Canadian businessmanCharles Desmarais, president of the San Francisco Art InstituteFrance Chrétien Desmarais, Canadian lawyer and businesswoman, daughter of Jean Chrétien and wife of André DesmaraisFrançois-Séraphin Régnier-Desmarais (1632–1713), French ecclesiastic, grammarian, diplomat and poetJames Desmarais (born 1979), Canadian professional ice hockey playerJean Noël Desmarais (1924–1995), Canadian physician, radiologist, and politician and brother of Louis DesmaraisLorraine Desmarais (born 1956), Canadian jazz pianist and composerLouis Desmarais (born 1923), member of the Canadian House of Commons from 1979-1984Ludger Desmarais, professional ice hockey player from 1926–1939Marcel-Marie Desmarais (1908–1994), Quebec writer, preacher and broadcasterOdilon Desmarais (1854–1904), Quebec lawyer, judge and politicianOvide E. Desmarais (1919–1998), American author of books and detective storiesPaul Desmarais (1927–2013), Canadian billionaire and CEO of the Power Corporation of CanadaPaul Desmarais, Jr. (born 1954), Canadian businessman, son of Paul Desmarais, and chairman of Power Corporation of CanadaPierre DesMarais, Canadian politician and Chairman of Montreal's Executive Committee 1954-1957