"This decision was based solely on the fact that this is my last year to play and my parents and I felt like it was the right move to make," Thomas said in a statement.
"Carlton came to me recently to discuss his thoughts," coach Mark Richt said. "I understand his decision and appreciate all the contributions he's made to our program."
A native of Frostproof, Fla., Thomas played in 27 career games, including two starts. He rushed for 725 yards and four touchdowns on 159 career carries.
"I connected with the University of Georgia during my time in Athens on a personal level and will never forget the relationships I developed and the life lessons I learned," Thomas said. "I know I will take everything I learned over the last several years and try to spread the knowledge wherever life takes me in the future."