The third instalment of Todd Phillips's comedy will see the doctor-turned-comedian's supporting role expanded to a major one, according to The Hollywood Reporter.
His character Mr Chow has become a firm fan favourite following his appearance in the original movie and its first sequel.
Jeong is arranging dates for filming that will not clash with his work on NBC's Community.
Stars Bradley Cooper, Ed Helms and Zach Galifianakis have already signed on to return for The Hangover 3.
Phillips has said that the third movie will be the last in the franchise.
Jeong is also known for his roles in films including Transformers: Dark of the Moon, Knocked Up and Despicable Me.
The Hangover: Part 3 will debut on May 24, 2013.