Justin Irvin Upton (born August 25, 1987, in Norfolk, Virginia) is an American Major League Baseball right fielder for the Arizona Diamondbacks. He was selected first overall by the Diamondbacks in the 2005 Major League Baseball Draft.

He previously an all-district shortstop for Great Bridge High School in Chesapeake, Virginia, and was awarded the AFLAC National High School Player of the Year Award. He is also the brother of Tampa Bay Rays center fielder B.J. Upton, who was taken # 2 in the 2002 draft.

Upton was originally drafted as a shortstop, but was later moved to center field because the Diamondbacks already had Stephen Drew at the position.