Luiz Mattar (born August 18, 1963) is a former professional tennis player from Brazil.

With seven ATP singles titles in tournaments of the Association of Professional Tennis Players, he is the second Brazilian tennis player, after Gustavo Kuerten, with more ATP titles in his career.

This feat has only been matched by Gustavo Kuerten who led the Brazilian team again to the semi-final in 2000.

He started his professional career only at the age of 22, unlike most tennis players who started their careers at 18 or earlier, after dropping out in his last year of engineering at Mackenzie Presbyterian University in São Paulo.

[3] After retiring from tennis he became an entrepreneur and is the founder of TIVIT, one of Brazil's largest information technology service providers.