The media mogul - who quit her successful chat show earlier this year after 25 years to focus on running her own network - made $290 million between May 2010 and May 2011 to top Forbes` HighestEarning Hollywood Women list, ahead of celebrities including Lady Gaga, Gisele Bundchen and Ellen DeGeneres.
Her closest competitor `You and I` hitmaker Gaga only managed to make $90 million in the same period, $200 million less than Oprah, while former `Real Housewives of New York` star Bethenny Frankel was third with $55 million thanks to her New York Times bestseller and Skinnygirl food empire.
Supermodel Gisele, talk show host Ellen, TV`s Judge Judy Sheindlin and country superstar Taylor Swift all tied for fourth place with earnings of $45 million.
Katy Perry banked $44 million from her world tour, album sales and endorsement deals and pregnant pop star Beyonce Knowles raked in $35 million last year, completing the top ten with romance author Danielle Steel - the most successful female novelist of all time - who earned the same amount.
Forbes Top 10 HighestEarning Hollywood Women 2011: