Roberson shared the top job with Nate Sudfeld last year, and the two quarterbacks competed again during spring practice with no clear-cut starter named.
"I want to thank the coaching staff, my teammates and Indiana University for all of their support over the last three years," Roberson said in a statement. "My time in Bloomington will always hold a special place in my heart. I wish everyone at IU all the best as I move on to the next chapter in my life."
On Friday, Roberson took to Twitter to announce he's headed to Illinois State, an FCS school.
Im excited about this chapter and wil be attending illinois state
- Tre Roberson (@tre5_roberson) June 13, 2014
Roberson became the first true freshman to start at quarterback for Indiana in 2011. He entered 2012 as the starter but suffered a season-ending broken leg in the second game at Massachusetts.
The Indianapolis native returned in 2013 and started four games, passing for 1,128 yards with 15 touchdowns and four interceptions and adding 423 rush yards and five touchdowns.
Roberson has a redshirt season available and two full years of eligibility remaining because he received a medical hardship for 2012. He will be eligible to play this season for Illinois State.
Sudfeld, who led Indiana with 2,523 passing yards and 21 touchdowns with nine interceptions in 2013, is expected to enter the season as the starter.