The 'Hangover' actor - who was recently named People magazine's Sexiest Man Alive - is said to have grown close to the 'Avatar' star when they appeared alongside each other in upcoming movie 'The Words' earlier this year, and the pair are now allegedly planning a romantic skiing break in the Rocky Mountains.
A source told E! News: "They are very happy. They are totally dating."
The 36-year-old actor - who split from Renee Zellweger earlier this year and has previously been linked to the likes of Jennifer Lopez and Olivia Wilde - recently admitted romancing a fellow celebrity can be more trouble-free as they understand life in the spotlight.
He said: "Connection and chemistry are amazing things and if the other person is used to being in the media, it makes things easier."
However, he recently claimed he is too busy with his career to find the time to date anyone.
Bradley explained: "I'm filming 'The Place Beyond The Pines' at the moment with Ryan Gosling in New York, so that's taking up a lot of my time. It's really exciting, but it doesn't leave much time for a relationship."
Meanwhile, Zoe announced she and her fiance of 11 years, Keith Britton, were splitting amicably last month.