"I am here today because Stacey Abrams cares about the things that matter," Winfrey told a cheering crowd in Cobb. She will also campaign for Abrams at a second town hall meeting, as well as knock on doors in DeKalb County on Thursday.
Former president Barack Obama will hold a rally for Abrams at Forbes Arena on Morehouse College campus in Atlanta on Friday, Nov. 2 at 5 p.m.aa
In a statement to BuzzFeed News, Abrams said: "I am honored to have Oprah join me for uplifting and honest conversations with voters about the clear choice before us in this election."
Abrams previously accused her opponent Brian Kemp of using his position as Georgia secretary of state to gain an unfair advantage over her.
Kemp reportedly purged the voter rolls of 300,000 registered voters whose voter registration forms contained errors.
Last week, a federal judge ruled that elections officials must contact voters and offer them the chance to correct their forms.