Joseph William Kelly (born June 9, 1988) is an American professional baseball pitcher for the Boston Red Sox of Major League Baseball (MLB). He has served as both a starter and a reliever.  

Kelly has also gained publicity for his comical repertoire, such as skillfully dancing in the outfield during practice, disguising himself while interviewing the unwitting rapper Nelly, and engaging in lengthy staredown with Los Angeles Dodgers outfielder Scott Van Slyke before a 2013 National League Championship Series game.

In the summer of 2014, the St. Louis Cardinals traded Joe Kelly, along with teammate Allen Craig, to the Boston Red Sox.