Castonguay is a surname. Notable people with this surname include:
Alexandre Castonguay (born 1968), Canadian media artist Antoine Castonguay (1881–1959), Canadian politician Charles Castonguay (born 1940), Canadian mathematician Claude Castonguay (1929–2020), Canadian politician Émilie Castonguay, Canadian sports agent Éric Castonguay (born 1987), Canadian ice hockey player Jeannot Castonguay (born 1944), Canadian politician Marilyn Castonguay, Canadian actress Mike Castonguay, American musician Roch Castonguay, Canadian film and television actor
See also