The Fresh Prince of Bel-Air star told BBC Breakfast that he is delighted with Obama's impact since 2008 and says he is confident the electorate will reinstate the 50-year-old.
While promoting Men in Black III, the actor digressed: "It definitely has to be another victory and I think what he represents for America, what he represents for the world.
"He needs another four more years to bring it to fruition... he's done a really good job and he just needs the four more years to finish it."
Smith, who has always backed the Democrat, lauded Obama's change of stance on supporting gay marriage.
The 43-year-old movie star added that he would be "the most natural choice" for the rumoured film covering Obama's life story and 2008 presidential election victory.
Contrary to comments made last Friday, Smith revealed that he would "consider" the role if offered it.
Watch the trailer for Men in Black III below: