The 30-year-old forward, a four-time NBA Most Valuable Player, also holds a player option for 2016-17 which would increase his contract to a maximum of $46.9 million spread over two years, CNBC said.
James, who led the injury-hit Cavaliers to last season's NBA Finals where they lost 4-2 to the Golden State Warriors, opted out of a two-year deal on June 29 to reach free agency though it was widely expected he would remain with Cleveland.
Cleveland fans can now look forward to the return of their illustrious 'Big Three' with All-Star forward Kevin Love and point guard Kyrie Irving having both agreed to maximum contracts.
Love, who missed the NBA Finals after dislocating his shoulder, said on Thursday his deal was "inked and official" after he had sought the advice of James once free agency opened.
"He happened to be in Los Angeles the same time I was ... we agreed on a lot of things," three-time All-Star Love, speaking in a video posted on The Players' Tribune website, said of his poolside chat with James.
"I expressed this to LeBron ... I can actually go wherever I want and pick the team I want to play for. But every time I went through the different scenarios I always came out at the same place ... to be in Cleveland and try to win championships.
"I would be able to really help this team win and going forward make a very big impact on this team and on this city, trying to bring home a championship or championships."
