Castanho (, meaning brown) is a common surname in Portuguese. Abraham Castanho (17th century), Spanish poet Bianca Castanho (1979), Brazilian actress José Carlos Castanho de Almeida (1930–2022), Brazilian Roman Catholic prelate Klara Castanho (2000), Brazilian actress and singer Luiz Castanho de Almeida (1904–1981), Brazilian historian Thiago Castanho (1975), Brazilian guitarist, record producer, painter and sculptor