Jeffrey Matthew Duncan (born December 9, 1978) is an American baseball coach and former Major League Baseball outfielder for the New York Mets. He is the head baseball coach at Kent State University. Duncan played college baseball at Iowa State University in 1998 before transferring to Arizona State University from 1999 to 2000 to play for coach Pat Murphy. After a standout college career, he would be drafted in the 7th round in 2000 by the New York Mets. He then played in the Major Leagues for the New York Mets in 2003 and 2004. Duncan also played in the San Diego Padres, Los Angeles Dodgers, and Toronto Blue-Jays organizations. He hit and threw left-handed.