Nature Boy reportedly confessed about his 5-figure conquest while shooting a "30 for 30" special for ESPN -- a special that's set to air in November.
But apparently Naitch, who's famously referred to his penis as "Space Mountain" for years while asking women if they want a ride ... is now embarrassed about his sex life.
"I wish I hadn't said that because of my grandkids," Flair told People ... insisting, "I only love one now" -- a reference to his fiancee, Wendy Barlow.
FYI, Flair is 68 years old -- so if he started banging at 15 ... we're talking an average of 188 women per year (or 3.6 women per week).
Chamberlain claimed to have slept with 20,000 women.