The US billionaire has written the comment under a video of himself giving an interview to CNBC in 2023, with him saying that he would like to see "a normal person with common sense" as the new US president.
"I cannot see myself voting for Biden this time," Musk wrote on X on Sunday.
The US presidential election will be held on November 5. Donald Trump and former US Ambassador to the UN Nikki Haley are vying for the nomination as a candidate from the Republican Party. Incumbent US President Joe Biden announced his bid for reelection in April 2023 from the Democratic Party.