Forbes complied the list, which covers June 2013 until June 2014.
Sandra, 50, saw her pay cheque rocket in the past year thanks to her starring role in the Alfonso Cuaron's Gravity, for which she received a best actress Oscar nomination.
The sci-fi thriller took $716million at the worldwide box-office, while Sandra’s other film, The Heat, also starring Melissa McCarthy, earned $230million.
In second place was Jennifer Lawrence. The 23-year-old starred in a number of hit films in the last 12 months, including Hunger Games: Catching Fire, American Hustle and X Men: Days of Future Past and Present, earning her $34million.
Jennifer Aniston took home $31million following her turn in We’re The Millers, while Iron Man actress Gwyneth Paltrow earned $19million.
Last year’s highest paid actress Angelina Jolie was named in fifth place with $18million.
In contrast, Robert Downey Jr was named Hollywood’s top earning male star, with $75million in earnings thanks to the Iron Man trilogy and the Avengers films; Marvel has made almost $4billion on films starring Robert, not including merchandise.
Forbes estimates that the female top ten earned $226million compared to the $419million made by the men.
Forbes highest-earning actresses 2014:
1. Sandra Bullock - $51million (£31million)
2. Jennifer Lawrence - $34million (£20million)
3. Jennifer Aniston - $31million (£18million)
4. Gwyneth Paltrow - $19million (£11million)
5. Angelina Jolie - $18million (£10.6million)
6. Cameron Diaz - $18million (£10.6million)
7. Scarlett Johansson - $17million (£10million)
8. Amy Adams - $13million (£7.7million)
9. Natalie Portman - $13million (£7.7million)
10. Kristen Stewart - $12million (£7.1million)