Lee will continue in his role on the Boston bench until the team is eliminated from the playoffs before replacing Steve Clifford in Charlotte, the team said.
The Hornets were 21-61 and Clifford, who twice served as head coach of the franchise, will remain with the organization in a front office role.
Lee was hired by president of basketball operations Jeff Peterson in a reunion with the Hornets. They were both in the Atlanta Hawks' organisation at the outset of their NBA careers. Lee spent five years as an assistant coach for former Hawks (2014) and Milwaukee Bucks (2018-22) coach Mike Budenholzer and was hired to be an assistant coach on Joe Mazzulla's staff in 2023.
"We are excited to welcome Charles Lee as the head coach of Charlotte Hornets," Peterson said. "His high character and his ability to connect with players while also instilling a culture of accountability will serve us well as we construct a competitive team built for long-term success.
"Charles possesses a championship pedigree with a wide range of basketball knowledge and NBA experience, has a tremendous work ethic and is a great communicator. He shares our vision for this organization, and I look forward to partnering with him in building something special here in the Carolinas."
Lee agreed to a four-year deal, according to ESPN.
"The opportunity to be the head coach of the Charlotte Hornets is a dream come true," Lee said. "I want to thank Rick Schnall, Gabe Plotkin and Jeff Peterson for the trust they are placing in me to lead this team.
"The Hornets have a talented young core of players and I'm excited about our future and what we can build here. There are few places as passionate about basketball as the Carolinas, and I look forward to coming to Charlotte and getting to work."
That move came after Lee was one of three finalists to become head coach of the Detroit Pistons.
Lee was viewed as a rising candidate in the NBA for the past two offseasons. He interviewed to be head coach of the Sacramento Kings in 2022 and the Lakers requested permission to interview him when another Bucks assistant, Darvin Ham, was selected to be Lakers head coach.
