Plácido Enrique Polanco (pronounced /ˈplɑːsidoʊ ɛnˈriːkeɪ poʊˈlɑːŋkoʊ/; born October 10, 1975 in Santo Domingo, Dominican Republic) is a Major League Baseball player for the Detroit Tigers who has also played for the St. Louis Cardinals and Philadelphia Phillies. He is a second baseman, but in the past has played shortstop and third base.

Polanco is also a close friend of former teammate and current Cardinals first baseman Albert Pujols, and Pujols is godfather to Polanco's son Ismael. In accordance with his gentle nature, Polanco's name, translated in Spanish, literally means 'Placid Burro.'

In a July 9, 2008, ceremony at Comerica Park prior to the Tigers-Indians game, Polanco received his U.S. citizenship, along with 99 other people. He wore his Tigers uniform for the ceremony.