Look up castaldo in Wiktionary, the free dictionary.
Castaldo is a surname. Notable people with the surname include:
- Alfonso Castaldo (1890–1966), Italian Roman Catholic cardinal
- Joseph Castaldo (1927–2000), American composer
- Matteo Castaldo (born 1985), Italian rower
- Michéal Castaldo (born 1962), Italian tenor, music producer and composer