Mateus Galiano da Costa is an Angolan international football player
Mateus Galiano da Costa, simply 'Mateus', plays for C.D. Nacional in the Portuguese first division, as a forward.
After playing in his first professional for modest Portuguese squads (he had a stint with Sporting Clube de Portugal, but never moved past its B side), Mateus signed, in January 2006, with Gil Vicente FC, then in the first division. He scored in his debut on 5 February, in a 5–0 home win over Vitória de Setúbal.
However, Mateus was at the centre of a judicial controversy that erupted in Portuguese football, known as Caso Mateus (Mateus affair or files), after a supposedly illegal registration by the Barcelos team. After a lengthy judicial battle between Gil and C.F. Os Belenenses, the former was eventually relegated.
After an uneventful season with Gil Vicente in the second division, greatly delayed by the legal consequences, Mateus joined Boavista F.C. for 2007–08, with his new team also being relegated for irregularities.
In the 2008–09 season, Mateus moved to Madeira's C.D. Nacional, being an important offensive element, whether as starter or from the bench, as the club eventually qualified for the UEFA Europa League.
An Angolan international, Mateus was called-up to the 2006 FIFA World Cup, playing in all three group stage matches, including the entire match against Portugal (0–1).