Cassini is a surname. Notable people with the surname include:
Arthur Cassini (1836–1913), Russian diplomat
César-François Cassini de Thury (1714–1784), French astronomer and cartographer, son of Jacques, who developed the Cassini projection
Dominique, comte de Cassini (1748–1845), first Count Cassini, French astronomer and cartographer, son of César-François
Giovanni Domenico Cassini (1625–1712), also known as Jean-Dominique Cassini, Italian-French astronomer
Henri Cassini (1781–1832), known as Henri Cassini, French botanist, youngest son of Jean-Dominique
Igor Cassini (1915–2002), American gossip columnist, writing as "Cholly Knickerbocker"
Jacques Cassini (1677–1756), French astronomer, son of Giovanni Domenico
Oleg Cassini (1913–2006), American fashion designer
