Rikuto Tamai of Japan took silver and Britain's Noah Williams finished in third place to claim the bronze medal.
Four-time Olympian Cao successfully defended his title against 17-year-old Tamai, who delivered some of Saturday's best dives in an exhilarating final that made the crowd erupt in roars over and again.
His win meant China took all eight diving golds up for grabs in Paris.
Tamai had wowed fans with a superbly executed first dive, only to be overtaken by Cao, who scored 96.90 points with an average score of 9.5 from the judges to establish a strong lead.
The Japanese teenager came back with a stronger performance in the second round to overtake Cao and continued with a top-notch third dive.
Tamai however had a problematic fifth dive which ended with a massive splash. That mistake eventually cost him the gold, allowing Cao to widen his lead as the Chinese veteran dived with composure to finish off on 547.50 points.
Britain's Williams, who won a silver medal in the synchronised event with Tom Daley two weeks ago, rebounded well in his last two dives after slipping to ninth in the third round, to claim the third place on the podium.
With his Paris title, Cao has now won gold medals in four consecutive Olympics.
As well as winning the event in Tokyo, he also won the synchronised 10-metre platform in the London Games in 2012 and individual 3-metre springboard in Rio four years later.
Cao's medal tally also includes a silver in the synchronised 10-metre event in Tokyo and a bronze in the synchronised 3-metre event in Rio.
China's world champion Yang Hao, who came second in the semi-final, was completely off his game in the final with one messy dive after another to end up the last place.
