Rosier is a surname. Notable people with the surname include:
Cathy Rosier (1945–2004), Guadeloupe-born model and actress
Frederick Rosier (1915–1998), Royal Air Force commander
Jean-Louis Rosier (20th century), French racecar driver
Joseph Rosier (1870–1951), United States Senator from West Virginia
Louis Rosier (1905–1956), racing driver
Michèle Rosier (1930- ), film director, screenwriter and fashion designer