Little attended Hillside High School in Durham, North Carolina, where he played football, basketball and ran track. He graduated in the spring of 2007. Little primarily played tailback during his junior year as well as spending some time at wide receiver. His vertical jump was 40.0" and his broad jump was 10-1. North Carolina, Florida, Michigan, Notre Dame, Ohio State, and USC all offered scholarships for Little to attend their respective colleges. He visited North Carolina on October 13, 2006, Notre Dame on September 16, 2006, and Ohio State on September 23, 2006. He later verbally committed to the University of North Carolina. Little had a high school GPA of 2.7 and scored 930 on the SAT. He played in the 2007 U.S. Army All-American Bowl.
In track & field, Little competed in sprints and jumps. He was timed at 11.1 seconds in the 100 meters, cleared 1.92 meters in the high jump and got a top-jump of 6.38 meters in the long jump.
As a freshman in college during 2007, he had a total of 300 rushing yards and 99 receiving yards. Little also returned kickoffs for total of 145 yards. As a sophomore, he had a total of 339 rushing yards, 146 receiving yards, and 141 return yards. During his final collegiate season, as a junior, Little had 166 rushing yards, 724 receiving yards, and 222 kickoff return yards. As a senior in 2010, Little did not play, as he was ruled ineligible by the NCAA for lying to investigators about receiving travel accommodations and jewelry.
On November 19, 2013, the University of North Carolina sent a disassociation letter to Little, Marvin Austin, and Robert Quinn for the improper benefits taken during their time at the university. The three athletes are prohibited from contacting current North Carolina athletes and are not allowed inside the Kenan Football Center or other athletic facilities on campus.
As a freshman in college, Greg Little also played basketball on the University of North Carolina basketball team that went to the Final 4 during the 2007-08 season. He played in 10 games and averaged 1.5ppg.
Little was drafted by the Cleveland Browns in the second round (59th overall) of the 2011 NFL Draft.
Greg Little finished the 2011 season leading the Cleveland Browns in catches and receiving yards. Little was second among rookies in catches, behind first round pick A. J. Green and fifth in yards behind A.J. Green, Torrey Smith, Julio Jones, and Doug Baldwin. He also finished with two touchdowns.
On May 16, 2014, Little was released by the Browns after 3 seasons with the team.
On May 19, 2014, Little was claimed off waviers from the Browns by the Oakland Raiders. Little was released on August 30, 2014.
On October 14, 2014, Little signed with the Cincinnati Bengals. He was released by the Bengals on February 28, 2015.
On July 30, 2015, Little re-signed with the Bengals. He was later released again by the Bengals on October 31, 2015.
On January 12, 2016 Little signed with the Buffalo Bills a future contract. On August 30, 2016, Little was released by the Bills.