Chizik had been out of coaching, spending the past several years working at ESPN for SEC Network.
"Gene has been a valued member of our college football coverage since SEC Network's inaugural season in 2014," ESPN senior vice president of production Lee Fitting said in a statement. "Over the past five seasons since his return to ESPN, 'Coach Chiz' has instilled his passion for the game in his colleagues and our viewers, and we're all better for it. We wish him the very best in his newest chapter at UNC."
Before working in television, Chizik was defensive coordinator at North Carolina from 2015 to 2016, helping the Tar Heels become the most improved defensive unit in the country.
He also worked for North Carolina coach Mack Brown previously as defensive coordinator at Texas from 2005 to '06.
In addition, North Carolina hired Indiana defensive coordinator Charlton Warren as co-defensive coordinator and defensive backs coach. Warren worked with Chizik previously at North Carolina.
Earlier in the week, North Carolina announced defensive coordinator Jay Bateman and outside linebackers/special teams coach Jovan Dewitt wouldn't return.
North Carolina struggled on defense this past season, allowing 32.1 points per game in a year that began with ACC championship hopes.
"Having coached here previously, I know this is a special place and I'm excited to help the program take the next step towards competing for and winning championships," Chizik said in a statement. "I'm also excited to work with Coach Brown and a number of the assistants again. I know this group does things the right way and for the right reasons, which is really important to me. We've had a number of opportunities to get back into coaching, but this one is the total package. I've seen what the program has become since Coach Brown's return, I know where it's headed, and I'm excited to be a part of it. We can't wait to get to Chapel Hill, meet all the guys, and get to work."