Bernie Sanders' campaign is hoping the latest endorsement will help him with black voters.
Spike Lee released a pro-Sanders ad in South Carolina Tuesday.
In a 60-second ad, Lee says "When Bernie gets into the White House, he will do the right thing."
Sanders is looking to increase his support among black voters.
A recent CNN-ORC South Carolina poll showed Clinton with 65-percent support from black voters.
In the ad, Lee also pushes for voters to support Sanders instead of "corporate puppets."
South Carolina Democrats hold their primary on Saturday.
Meanwhile, Sanders says he is "delighted" that Hillary Clinton is "adopting more and more of the positions" he has advocated.
"That is good. And she has started to use our language, our rhetoric, our positions because she sees them working," Sanders says.
"The people of the U.S. need to know the difference between hastily adopted campaign rhetoric and the real record and the long held ideas of candidates."
Spike Lee backs Bernie Sanders for president