Matthew Edward Diaz (pronounced /ˈdaɪ.əz/ dy-əz; born March 3, 1978 in Portland, Oregon) is a Major League Baseball outfielder who plays for the Pittsburgh Pirates. He grew up in Lakeland, Florida.
As a two-year starter at Florida State University, Diaz helped lead the Seminoles to two College World Series appearances, including the 1999 title game vs. the University of Miami. He was named the Sporting News man of the Year in 1998, and a First Team All-American (American Baseball Coaches Association, National Baseball College Writers' Association) in 1999.
He was drafted by the Tampa Bay Devil Rays in the 1999 Major League Baseball Draft in the 17th round.