João José Vaz (9 March 1859, in Setúbal – 17 February 1931, in Lisbon) was a Portuguese painter and decorator who specialized in maritime subjects.

In 1872, he enrolled at the "Academia das Belas-Artes" (now part of the University of Lisbon), where he studied under António da Silva Porto.

He was especially well known for his maritime paintings and provided illustrations for several magazines, including Branco e Negro[2] (1896-1898), Atlantida[3] (1915-1920) and Contemporânea[4] (1915-1926).

In 1884, he became a Professor at the "Escola Industrial Afonso Domingues" (named after a 14th-century architect), where he was later promoted to Director.

In 1912, he served on a government commission to establish new curricula for commercial and industrial education in the primary and secondary schools.