Gregori Emilio Aquino Valera (/əˈkiːnoʊ/; Spanish pronunciation: [aˈkino]; born January 11, 1978) is a Dominican former professional baseball pitcher.

He previously played for the Arizona Diamondbacks, Milwaukee Brewers, Baltimore Orioles, and Cleveland Indians.

After spending the next decade in the Diamondbacks' farm system, he made his major league debut on July 2, 2004, against the Minnesota Twins.

[3] Aquino began the 2007 season on the Brewers roster, but was optioned to the Triple-A Nashville Sounds on April 21.

On April 19, 2013, Aquino signed with the Sugar Land Skeeters of the Atlantic League of Professional Baseball.