Microsoft co-founder Bill Gates, 59, tops the 2015 poll, known as the NiC 50, just ahead of new U.S. presidential hopeful Hillary Clinton at two.

Winfrey places third on the countdown, with editors noting her "mantra of positivity, kindness, forgiveness and candor mixed with self-deprecation" for showing fans how to build an empire.

Comedienne DeGeneres comes in at 10, while Oscar winner Streep is at 12, Madonna at 15 and Rosie Perez at 17.

Other notable entries include George Clooney, Gloria Estefan, Clint Eastwood, Barbra Streisand, Robert Downey, Jr., Kevin Spacey, Viola Davis, Sarah Jessica Parker, Brad Pitt, Scandal and Grey's Anatomy creator Shonda Rhimes and shock jock Howard Stern.