The celebrities will appear at the Lincoln Memorial on Wednesday, said The Hollywood Reporter.
Though it's recalled mainly for Martin Luther King's classic "I Have a Dream" speech, at the time the march was generally noted as the largest popular demonstration ever held in the nation's capital.
The crowd on that day was estimated to number at least 1 million with participants, speakers and performers drawn from many races and from all over the nation.
Television's Soledad O'Brien and Hill Harper will host the anniversary celebration, whose title is "Let Freedom Ring".
The commemoration will feature musical performances by LeAnn Rimes and Bebe Winans. Folk singers Peter, Paul and Mary, Bob Dylan and Joan Baez sang at the march half a century ago.
Winfrey and Whitaker are starring in Lee Daniels' "The Butler", a movie about a man who served seven presidents as a White House butler.