The senator from Vermont replied "yes" when asked on MSNBC if he would vote for Clinton.
Sanders, who this week signaled he did not believe he will win the Democratic nomination, said he will fight to shape the Democratic platform and focus on defeating Republican Donald Trump. Sanders has indicated he will remain in the race to influence Democratic policy at the party's convention next month.
"My job right now is to fight for the strongest possible platform at the Democratic convention," Sanders told MSNBC.
He also offered a strong rebuke to Trump, who has attempted to court Sanders voters ahead of a likely general election battle with Clinton. The New York tycoon has looked to seize on Sanders supporters' frustration with the established political system, which they contend is embodied by Clinton.
Sanders made clear Friday that he would focus on making sure Trump did not win.
"The issue right here is I'm going to do everything I can to defeat Donald Trump. I think Trump in so many ways would be a disaster for this country if he were to be elected president," he said. "We do not need a president whose cornerstone of his campaign is bigotry, is insulting Mexicans and Latinos and Muslims and women."
He said he planned to ensure the Democratic Party represented the interests of "working people" rather than Wall Street and big-money interests. Sanders, who had runaway fundraising success with mostly small donors, has repeatedly criticized Clinton for her ties to big banks.