John Gotti III looks to take out boxing legend Floyd Mayweather Jr.

The Gotti family is putting a hit on legendary boxer Floyd Mayweather Jr.

And they want 20,000 witnesses.

That’s because the grandson of fabled New York mob boss John Gotti will get his chance to whack Mayweather in the jaw in Florida on June 11.

The pay-per-view boxing match between John Gotti III and the Hall of Fame former five-division champ will take place at FLA Live Arena in Sunrise.

Gotti is no lightweight.

The brawler from Oyster Bay — son of John “Junior” Gotti — is 5-1 as an MMA fighter and sports a 2-0 record as a pro boxer.

The Gottis broke the code of omerta to discuss the exhibition showdown.

“This is a true ‘Rocky’ story. … I’m proud of my son and all that he has accomplished,” Junior Gotti told The Post. “When my son said he would leave his own mark in this world, he meant it. Here’s a kid who has no vices, doesn’t  smoke, doesn’t drink and has an awe-inspiring work ethic. On top of that he’s loyal to a fault. How do you not root for such a man?”

Gotti III said he was “honored to share the ring” with Mayweather and called the rumble, billed as  “Last Names Matter,” a “pinch me moment.”

Gotti grew up idolizing Mayweather, he told the media during last month’s promotional presser at The Gabriel Miami Downtown Hotel in Miami.

“But make no mistake, June 11 I’m bringing bad intentions to that man. I don’t care if it’s an exhibition or not. You signed to fight me, there’s no quarter. It’s kill or be killed,” he said.

The height difference — Gotti is 6 feet tall, Mayweather 5-foot-8 — was noticeable at the presser staredown.

Neither fighter disclosed how much they are making for the fight.

Mayweather, 46, retired from sanctioned competition after defeating MMA icon Conor McGregor in 2017.

However, he’s continued to box in exhibitions and squared off against the likes of Aaron Chalmers and Logan Paul.

Junior Gotti previously told The Post he and young John bonded by watching boxing and MMA.