Jon Jones will return to the octagon for the first time in three years, while Francis Ngannou has vacated the heavyweight belt to become a free agent.
UFC president Dana White announced Jones will fight for the heavyweight title at UFC 285 on March 5 against Ciryl Gane at T-Mobile Arena in Las Vegas.
Jones (26-1) will make his first appearance since February 2020 when he beat Dominick Reyes to defend his light heavyweight championship. He then vacated the title in hopes of getting a shot at the heavyweight belt.
White said he offered former heavyweight champion Ngannou the richest deal for a heavyweight in UFC history to fight Jones, but he turned it down. So White turned to Gane (11-1).
Ngannou, who has been in a long-standing contract dispute with the UFC, was released from his contract.