Cuban shared personal anecdotes about his experiences with Trump at a South by Southwest Festival audience in Austin, Texas on Sunday, saying he stopped supporting Trump after he "got to know him."
"The economic policies of his that are pretty much traditionally conservative I like.... But in terms of him personally, he's the Zoolander president," Cuban said to the audience, referring to a hit film comedy starring Ben Stiller.
The audience roared with laughter.
Cuban, who called himself a libertarian, spoke on a panel alongside car insurance marketplace The Zebra's Adam Lyons. Lyons scored Cuban as an investor in his company after cold emailing him a one paragraph pitch.
Cuban said there would be no appointment from Trump he would ever consider.
"His idea of efficiency is I would send him emails, his assistant would print it, he would write on it, and he would scan it," Cuban said. "He doesn't know how to use email."
The entrepreneur also noted Trump doesn't know how to use Google.
"Just think how efficient he could be if he learned how to use a search engine," Cuban said.
Overall, however, Cuban wants Trump's presidency to be successful.
"First of all he's our president," he said. "I don't care how he does personally, but I want the country to do well."
More From CNBC