Slightly over 15 million Twitter users voted in the poll with 51.8% voting in favor of reinstatement.
Trump will be reinstated," Musk tweeted.
Some users initially reported being unable to follow the reinstated account on Saturday evening.
He also said Twitter would not reinstate any banned users until there was a "clear process for doing so."
He has used Truth Social to promote his allies, criticize opponents and defend his reputation amid legal scrutiny from state, congressional and federal investigators.