Appearing on MSNBC's "Morning Joe," King was asked whether he would be comfortable with Paul as commander-in-chief.
“No I wouldn’t. I think his views would be disastrous," King said. "I think he appeals to the lowest common denominator."
The New York Republican said Paul represents an "isolationist wing from the 1930s" and is bringing debate on national security to a "hysterical level."
“He talks about the CIA trying to kill Americans having coffee in Starbucks when he talks about President Obama listening to his cell phone conversations," King said. "That to me is just feeding into paranoia."
"We do need an intelligent debate and I don’t think Rand Paul is capable of having that debate," he added.
Paul has indicated that he's taking the possibility of running for president very seriously. He reportedly asked Kentucky lawmakers to clarify state law preventing candidates from holding or running for two offices at the same time, which would allow him to retain his Senate seat should he launch an unsuccessful 2016 bid.
But a potential Paul presidency has been met with some skepticism. Wall Street Journal columnist Bret Stephens on Monday hit Paul on what he wrote were scant qualifications for the job, sarcastically arguing that what the Republican Party needs is "someone so nakedly unacceptable to the overwhelming majority of sane Americans that only the GOP could think of nominating him."