According to the provided information, Muhammad Ali stopped fighting professionally at the age of 39.
His final professional bout occurred in 1981. The reference states that following one final loss in 1981, to Trevor Berbick, the boxing great retired from the sport at age 39.
This marked the end of his remarkable career in boxing. Although he had brief retirements before, his retirement after the 1981 fight was his final decision.
Key points about his final fight and retirement:
- Final Opponent: Trevor Berbick
- Year: 1981
- Age at Retirement: 39
After this fight, Ali concluded his time in the ring, leaving behind an unparalleled legacy in the world of sports.
