João de Souza Mendes Júnior (23 June[1] 1892 – 10 July 1969) was a seven-time Brazilian chess champion and physician.
Prior to emergence of Henrique Mecking, he was Brazil's most accomplished (given the span of his dominance) chess player.
Born in the Azores, Portugal, Souza Mendes played in the Brazilian Chess Championship 29 times, winning in 1927 (the first year the tournament was held), 1928, 1929, 1930, 1943, 1954, and 1958.
He played for Brazil in Chess Olympiads at Buenos Aires 1939 and Helsinki 1952.
This biographical article relating to a Brazilian chess figure is a stub.