Saint-Cyr is a French surname. Notable people with the surname include:
Saint-Cyr Charles de Saint-Cyr (1875–1940), French footballer Claude Carra Saint-Cyr (1760–1830), French general Claude Saint-Cyr (1911–2002), French fashion designer Guillaume de Saint-Cyr, French athlete Jacques-Antoine de Révéroni Saint-Cyr (1767–1829), French man of letters Laurent, Marquis de Gouvion Saint-Cyr (1764–1830), Marshal of France
St. Cyr Adolphus Frederic St. Sure (1869–1949), United States District Judge.(name anglicized) Cyprian St Cyr, pseudonym of Eric Berne, Canadian-American psychoanalyst and founder of Transactional Analysis John St. Cyr (1936-2022), American politician and judge Johnny St. Cyr (1890–1966), American banjoist Jordan St. Cyr, Canadian recording artist Lili St. Cyr (1918–1999), pseudonym of Willis Marie Van Schaac, prominent American burlesque stripper