José Javier Valentín Rosario (born September 19, 1975 in Manatí, Puerto Rico) is a catcher in Major League Baseball with the New York Mets organization. From 2004-2008, he played for the Cincinnati Reds after playing with the Tampa Bay Devil Rays (2003) and playing in four brief stints for the Minnesota Twins from 1997-2002. He is the younger brother of former Major League Baseball second baseman José Valentín. In 2005, he hit .281 with a career-high 14 home runs as a backup catcher for the Reds. He is a switch-hitter. Valentín played briefly at first base and even more infrequently at third base in his time with Cincinnati.
Valentín was drafted on June 3, 1993, by the Minnesota Twins in the third round of the 1993 Major League Baseball Draft. He made his major league debut on September 13, 1997, and ended up playing three seasons for the Twins.
On November 15, 2002, the Twins traded him with Matt Kinney to the Milwaukee Brewers for Minor League prospects Gerry Oakes and Matt Yeatman. A few months later, the Brewers sent him to the Tampa Bay Devil Rays for Jason Conti.