Clinton said that given the size of the universe and the discovery of new planets, he believes we may not be alone.
He also says when he was president, he had his aides research Area 51 in Nevada and the supposed 1947 alien incident at Roswell, New Mexico.
Clinton: "First I had people go look at the records on Area 51, to make sure there was no alien down there."
Kimmel: "If you saw that there were aliens down there, would you tell us?"
Clinton: "I would. I would. If we were visited someday I wouldn't be surprised. I just hope it's not like Independence Day. The movie."
Kimmel: "Yeah right."
You can watch the YouTube clip here.
You can catch "Jimmy Kimmel Live" weeknights at 11:35 p.m., right after ABC7 News at 11.