Jeffrey Glen Baker (born June 21, 1981, in Bad Kissingen, West Germany) is a professional baseball player in Major League Baseball who plays several positions as a utility player for the Chicago Cubs. He bats and throws right-handed. He was the 1999 Virginia Prep Player of the Year.

Baker made his Major League debut in 2005, as the Opening Day third baseman for the Colorado Rockies, playing a total of 12 games. He had been added to the Rockies lineup as a replacement for injured third baseman Garrett Atkins and on the return of Atkins, Baker was assigned to the Colorado Springs Sky Sox, the Rockies Triple-A affiliate.

Baker was drafted by the Rockies in 2004 after playing college baseball at Clemson University. While at Clemson, Baker set the school record for career home runs with 59 HR, a feat he accomplished in three years. He was a three-time Baseball America All-American.