Robert Bigelow, 73, CEO of Bigelow Aerospace, appeared in the latest edition of prime time CBS current affairs show 60 Minutes.
But, during the programme, which looked at his work on developing the expandable spacecraft, which inflate in space and could one day change how humans live and work in zero gravity, he made the sensational admission.
He described a UFO encounter his grandparents had on an undisclosed date while driving on a canyon road outside Las Vegas.
He said: “It really sped up and came right into their face and filled up the entire windshield of the car.
“And it took off at a right angle and shot off into the distance.”
He told reporter Lara Logan it began an obsession with aliens and is the reason behind his “alien logo” for Bigelow Aerospace.
He said he had since had his own “close encounters”, but did not go into details.
The business guru also revealed being a subscriber to a widely held conspiracy theory that the US Government, and others across the globe, know that aliens are here on Earth, and even interact with them, but it is all kept top secret from the public amid fears over the impact it would have on religion and the rule of law.
Ms Logan described it as “the kind of conversation you don’t ordinarily have with an accomplished CEO”.
She asked him if he believed in aliens?
He said: “I’m absolutely convinced. That’s all there is to it.
“There has been and is an existing presence, an ET presence.
“And I spent millions and millions and millions – I probably spent more as an individual than anybody else in the United States has ever spent on this subject.”
Ms Logan asked: “Is it risky for you to say in public that you believe in UFOs and aliens?
“You don’t worry that some people will say, ‘Did you hear that guy, he sounds like he’s crazy?'”
But, he replied: “I don’t give a damn. I don’t care.
“It’s not going to make a difference. It’s not going to change the reality of what I know.”
She said: “Do you imagine that in our space travels we will encounter other forms of intelligent life?”
Mr Bigelow addded: “You don’t have to go anywhere.
“It’s just like right under people’s noses.”
The Federal Aviation Administration (FAA) confirmed to CBS that for several years, it had referred reports of UFOs and other unexplained phenomena to a company Bigelow owns.
Ms Logan said: “Robert Bigelow’s quirky and he knows it, but when you have as much money as he does, no one – not even NASA – seems to care.”
Stephen Bassett is the executive director of the Paradigm Research Group (PRG), which is campaigning for the US Government to life an alleged “truth embargo” about the existence of aliens.
He said: “Billionaire Robert Bigelow of Bigelow Aerospace spoke truth to power and finally said publicly what he and hundreds of millions of people around the world already know to be true.
“And he said it on CBS 60 Minutes Sunday night. There is an extraterrestrial presence engaging the human race.
“How many military officers, political figures, intelligence agents, scientists, entertainers, and, yes, billionaires have to speak this truth before the investigative journalists in America figure out the biggest news story in history has been right under their noses for 70 years?
“For decades CBS 60 Minutes has avoided the ET issue with great resolve.
“It simply would not cover the subject. Better late than never.
“PRG tips its hat to Robert Bigelow. Thank you.
“So, hello Elon Musk and Richard Branson. Would you care to say what you really think about the extraterrestrial presence? Nothing invigorates like speaking truth to power.”