Georgia. He participated in the GACA All-Star Game Georgia and All-American Game, and earned All-American honors from Parade and SuperPrep. Greg was named the "Georgia High School Association Player of the Year" and he was also the class 5A "Georgia Player of the Decade".

Reid was heavily recruited out of high school, earning five star ratings from both Rivals and Scouts, and received full scholarship offers from Alabama, Auburn, Florida, Florida State and Georgia, among others. 

He attended Florida State University from 2009 - 2012. Reid played all 38 games, completed 120 total tackles, 7 interceptions, 4 touchdowns and led the NCAA in punt return average. Greg was also named the defensive MVP of the 2010 Chick-fil-A Bowl.

Reid participated in the NFL Combine in 2013, and signed with the St. Louis Rams in March 2014. In April 2015, Reid joined the Arena Football League and was assigned to the Jacksonville Sharks. Reid's play led to him being named to the First-team All-Arena squad and also named the AFL Rookie of the Year.

In 2019, Greg Reid joined the Montreal Alouettes in the Canadian Football League.  Reid had 71 defensive tackles, knocked down 10 passes, made 3 interceptions, forced a fumble and recovered one during his first season. He was an integral member of the secondary on a resurgent Alouettes team and was named one of the 2019 CFL All-Stars. He signed a contract extension with the team through 2022.