Her ranking is powered by her gig as a judge on American Idol, a clothing line, a fragrance and millions of Twitter and Facebook followers.
Winfrey, who has admitted struggling with her OWN TV network after ending The Oprah Winfrey Show last year, kept her number two slot, earning an estimated $215 million.
Canadian pop star Justin Bieber, 18, stayed at number three, earning $71.7 million.
Pop star Rihanna made the list for the first time with estimated earnings of $69.1 million.
TOP 10 Most powerful celebrities
1. Jennifer Lopez 2. Oprah Winfrey 3. Justin Bieber 4. Rihanna 5. Lady Gaga 6. Britney Spears 7. Kim Kardashian 8. Katy Perry 9. Tom Cruise 10. Steven Spielberg