"I think, on a very drawn-out scale, I think I'm on the spectrum," Seinfeld told NBC's "Nightly News" late Thursday.
The multi-millionaire actor - famous for his semi-autobiographical 1990s sitcom "Seinfeld" - said he was "never paying attention to the right things."
He told NBC that he's very literal and the verbal expressions other people use can be puzzling.
"Basic social engagement is really a struggle. I'm very literal. When people talk to me and they use expressions, sometimes I don't know what they're saying," Seinfeld explained.
"But I don't see it as dysfunctional. I just think of it as an alternate mindset."
Seinfeld meets Australian Parliament in new video
The cause of autism, a complex neurodevelopmental disorder characterised by social withdrawal, is thought to be roughly split between genetic and environmental factors, according to experts.
