The Republican president, who has also revoked the security clearance for former President Joe Biden, defeated Clinton in the 2016 presidential election and Harris in last year's election.
"I have determined that it is no longer in the national interest for the following individuals to access classified information," Trump said in a late Friday memorandum that also included former Secretary of State Antony Blinken.
While the revocations may not have immediate impacts, it is another sign of the growing political rift in Washington as Trump seeks revenge on his perceived enemies.
The memorandum was issued hours after Trump arrived at his Bedminster, New Jersey, golf property for the weekend.
Trump also targeted Republican former Representative Liz Cheney, a sharp Trump critic, former Biden White House national security adviser Jake Sullivan and Fiona Hill, a Russia expert who served on his National Security Council during his first term.
Mark Zaid, a national security lawyer in Washington who represents whistleblowers, and Adam Kinzinger, a former Republican lawmaker who is a sharp Trump critic, were among several others who had their security clearances revoked.
He had already revoked the security clearance for Biden, denying the former president to the traditional access to US intelligence.
Former US presidents have traditionally received intelligence briefings so they can advise incumbent presidents on national security and foreign policy.
In 2021, Biden revoked the security clearance for Trump, who was then a former president.
