The 36-year-old actress won the prize at Glamour magazine's Women of the Year ceremony for co-founding fashion fitness line Fabletics, reported Female First.
The "How to Lose a Guy in 10 Days" actress said after listening to "an amazing feminist" she has started to feel deserving of being recognised for her work.
"I don't think you ever feel like you deserve awards, but I listened to an amazing feminist who said a lot of women feel they don't deserve the positions they're in - and they should stop feeling that way," she said.