Castelli is an Italian surname. Notable people with the surname include:
Annibale Castelli (c. 1570–c.1620), Italian painter, active near Bologna Bernardo Castelli (1557–1629), Italian painter of the late-Mannerist style, active mainly in Genoa and Liguria Francesco Castelli Borromini (1599–1667), Italian architect Giovanni Battista Castelli (1500 or 1509–1569 or 1579), Italian historical painter Matteo Castelli (c. 1555–1632), Swiss architect Teramo Castelli (1597–1659), Italian noble and Roman Catholic Theatine missionary Valerio Castelli (1624–1659), pre-eminent Ligurian painters
Alfredo Castelli (born 1947), Italian comic book author Anna Castelli Ferrieri (1918–2006), Italian architect and industrial designer Bartolomeo Castelli (1650–1730), Roman Catholic Bishop of Mazara del Vallo Benedetto Castelli (1577–1643), Italian mathematician Bernardino Castelli (1750–1810), Italian painter of portraits and religious figures Bertrand Castelli (1929–2008), French producer, director, lighting designer, choreographer and painter Clino Castelli (born 1944), Italian industrial designer and artist Clément Castelli (1870–1959), French painter David Castelli (1836–1901), Italian scholar and educator in the field of secular Jewish studies Davide Castelli (born 1999), Italian footballer Enrico Castelli (1909–1983), Italian basketball player Facundo Castelli (born 1995), Argentine professional footballer Filomena Delli Castelli (1916–2010), Italian politician Gaetano Castelli (born 1938), Italian painter and set designer Giovanni Paolo Castelli (1659–1730), Italian painter, active in Rome Giuseppe Castelli (1907–1942), Italian athlete Giuseppe Castelli (footballer) (1919–?), Italian professional football player. Guido Castelli (born 1965), Italian lawyer and politician Henri Castelli, artistic name of Henri Lincoln Fernandes Nascimento (born 1978), Brazilian actor and model Ignaz Franz Castelli, (1780–1862), Austrian dramatist Irene Castelli (born 1983), Italian gymnast Jeffrey W. Castelli, CIA officer Juan José Castelli (1764–1812), Member of the first national government of Argentina Laura Castelli (born 1986), Italian politician Leo Castelli (1907–1999), American art dealer Luciano Castelli (born 1951), Swiss painter, graphic artist, photographer, sculptor and musician María Castelli (born 1972), Argentine former field hockey player Marissa Castelli (born 1990), American pair skater Michelangelo Castelli (1808–1875), Italian politician Nino Castelli (1898–1925), Italian rower Paolo Castelli (born 1980), Italian footballer Pietro Castelli (1574–1662), Italian physician and botanist Raimondo Castelli (died 1670), Roman Catholic Bishop of Narni Rato Castelli (1904–1984), Brazilian footballer Richard Castelli (born 1961), producer, artistic consultant Roberto Castelli (boxer) (born 1969), Italian boxer Roberto Castelli (born 1946), former Italian Minister of Justice Samuel Castelli (born 1985), Mexican singer