The athlete famously known as "The Greatest" in boxing is Muhammad Ali. Born Cassius Clay, he became an iconic figure not only for his exceptional talent in the ring, winning the World Heavyweight Championship three times, but also for his outspoken personality and activism. Ali was famous for his unique fighting style, which included quick footwork and unmatched agility. His battles against notable opponents like Joe Frazier and George Foreman are etched in sports history, further cementing his legacy in the sport of boxing.