Senator Richard Burr, who as the committee's chairman is a congressional overseer of the US intelligence community, did not elaborate but his comment echoed those of the FBI.
"At this point I'm glad to say that it doesn't seem to have a terrorism nexus," he told reporters.
Islamic State had claimed that the shooter, Stephen Paddock, was a "soldier" who had recently converted to Islam.
US authorities have expressed skepticism about the claim. FBI special agent in charge in Las Vegas, Aaron Rouse, said investigators had found no evidence of a link.
Fifty-eight people were killed and more than 500 injured in the deadliest mass shooting in recent US history.
Police who burst into Paddock's room found that he had killed himself.