Castellanos is a Spanish surname. Notable people with the surname include:
Aarón Castellanos (1799–1880), Argentine businessman and military commander
Adolfo Jiménez Castellanos (1844–1929), last Spanish Governor General of Cuba
Agustin Walfredo Castellanos (1902—2000), Cuban-American physician
Alejandro Castellanos (born 1979), Honduran swimmer
Alex Castellanos (born 1954), Cuban-American political consultant
Alex Castellanos (baseball) (born 1986), American baseball player
Antonio Castellanos (born 1946), Mexican sculptor
Antonio Castellanos Mata (1947—2016), Spanish physicist
Carlos Castellanos (born 1961) Cuban-American illustrator and syndicated cartoonist co-creator of the 'Baldo' comic strip
Carlos Octavio Castellanos (born 1977), Mexican politician
César Castellanos (pastor), Colombian pastor
César Castellanos (politician) (1947–1998), Honduran politician
Claudia Rodríguez de Castellanos, Colombian Evangelical pastor
David Castellanos (born 1980), American retired soccer player
Deyna Castellanos (born 1999), Venezuelan women's soccer player
Enrique Abaroa Castellanos, Mexican landscape artist
Ernesto Juan Castellanos (born 1963), Cuban journalist and translator
Evencio Castellanos (1915–1984), Venezuelan pianist and classical musician
Francisco Xavier Castellanos (born 1953), American neuroscientist
Franklin Castellanos (born 1990), Honduran professional footballer
Gaby Castellanos (born 1970), Venezuelan businesswoman
Gumercindo Castellanos (born 1953), Mexican politician
Horacio Castellanos Moya (born 1957), Salvadoran writer
Jesus Castellanos (1878–1912), Cuban writer, journalist and lawyer
Jesús Antonio Castellanos (born 1978), Spanish footballer
John Castellanos (born 1957), American actor
José Castellanos Contreras (1893—1977), Salvadoran army colonel and diplomat
Juan de Castellanos, 16th-century Colombian poet
Julieta Castellanos (born 1954), Honduran sociologist and president of the National Autonomous University of Honduras
Julio Castellanos (1905–1947), Mexican painter and engraver
Leandro Castellanos (born 1984), Colombian footballer
Leonardo Castellanos y Castellanos (1862−1912), Mexican Roman Catholic bishop
Lincoln A. Castellanos, American actor
Luis Castellanos Tapias, Colombian lawyer
Manuel Castellanos López (born 1949), Cuban graphic artist
Marianella Castellanos (born 1984), Venezuelan softball player
Martín Ramos Castellanos (born 1961), Mexican politician affiliated to the Party of the Democratic Revolution
Migbelis Castellanos (born 1995), Venezuelan model and beauty queen
Milton Castellanos Everardo (1920–2011), Mexican politician and lawyer
Mirla Castellanos, Venezuelan singer
Nick Castellanos (born 1992), American baseball player
Nicolás Castellanos (born 1935), Spanish religious missionary in Bolivia
Pedro Castellanos (1902–1961), Mexican priest and architect
Rafael Antonio Castellanos (c. 1725–1791), Guatemalan classical composer
Roberto Domínguez Castellanos (born 1954), Mexican politician of the Institutional Revolutionary Party
Rosario Castellanos (1925–1974), Mexican poet and author
Santiago Castellanos (born 1977), Spanish former swimmer
Sara Isabel Castellanos Cortés (born 1946), Mexican politician
Sergio Arturo Castellanos (born 1969), Honduran politician
Teo Castellanos, American theater director
Víctor Castellanos (born 1934), Guatemalan former sports shooter
Victoriano Castellanos (1795–1862), President of Honduras
Vincent Castellanos (born 1961), American actor
Wilfredo Bustillo Castellanos (born 1958), Honduran politician