The school said in a statement that Miller will get a six-year contract.
Miller has been at UNCG for 10 seasons. Over the past five seasons, he has led the Spartans to three regular-season championships and two NCAA tournament appearances. UNCG has finished 13-5 or better in the Southern Conference in each of the past five seasons.
"I am honored to lead such a storied program and excited to get to work," Miller said in a statement. "I also can't thank UNCG enough because I wouldn't be here without my players and athletic director Kim Record. This last decade coaching the Spartans has been extremely rewarding."
This past season, the Spartans won both the regular-season and conference tournament titles in the SoCon before falling to 4-seed Florida State in the first round of the NCAA tournament.
Miller, 38, was one of the leading candidates for North Carolina's head-coaching vacancy earlier this month before the Tar Heels decided to hire Hubert Davis as Roy Williams' replacement. A North Carolina native, Miller played under Williams in Chapel Hill. He began his coaching career as an assistant coach at Elon and High Point before moving to UNC Greensboro as an assistant coach in 2010. He was promoted to head coach a year later.
Miller replaces John Brannen, who was fired last week after two seasons following an investigation into the program. The school placed Brannen on leave in early April after six players entered the transfer portal in the first three days following the end of the season.