Nearly 20% of those surveyed voted the Harry Potter author as the most inspirational female celebrity, with over a quarter voting for the Hackney-born Apprentice star.
Kingston University has estimated that there are 1.4 million freelancers in the UK; 14% more than in 1998.
"Brits are a nation of entrepreneurs becoming freelancers at a young age," Office Cavalry’s co-founder Andy Turner said.
Top female celebrities
1. JK Rowling
2. Katie Price
3. Karren Brady
4. Cheryl Cole
5. Oprah Winfrey
6. Victoria Beckham
7. Michelle Obama
8. Denise van Outen
9. Dannii Minogue
10. Kylie Minogue
Top male celebrities
1. Alan Sugar
2. Simon Cowell
3. Richard Branson
4. Peter Jones
5. Jamie Oliver
6. Bill Gates
7. Gordon Ramsay
8. Theo Paphitis
9. Jonathan Ross
10. David Beckham