Castello is a surname. Notable people with the surname include:
- Bernardo Castello (1557–1629), Italian Mannerist painter
- Dario Castello (c. 1590 – c. 1658), Italian composer
- Felix Castello (1595–1651), Spanish Baroque painter
- Giovanni Battista Castello (c. 1500 – c. 1579), Italian painter
- John Castello (1802–1877), Guyanese child actor and journalist
- Marie Castello (1915–2008), American psychic
- Sebastian Castellio (also spelled Castello, 1515–1563), French theologian
- Valerio Castello (1624–1659), Italian Baroque painter