The Academy Award winner, 31, returns $42.70 for every dollar she's paid thanks to the success of films like Black Swan, which earned a whopping $329 million at the box office. The other films included in her tally were No Strings Attached and Your Highness.
To calculate the list, Forbes examined each actor's last three movies that opened in more than 2,000 theaters. The magazine did not include films featuring the actors in supporting roles, which is why the superhero blockbuster Thor was not tallied in Portman's total.
Thanks in large part to the massively successful Twilight saga, Kristen Stewart -- who also happened to top Forbes' Highest-Paid Actresses list with $34.5 million in one year -- is hot on Portman's heels with an average return of $40.60 for every dollar paid. Shia LaBeouf placed third, returning $35.80 for every dollar he's paid.
The rest of the list includes Robert Pattinson, (No. 4, $31.70 returned for every $1 paid), Daniel Radcliffe (No. 5, $30.50 returned for every $1 paid), Taylor Lautner (No. 6, $29.50 returned for every $1 paid), Bradley Cooper (No. 7, $25 returned for every $1 paid), Dwyane "The Rock" Johnson (No. 8, $22.70 returned for every $1 paid), Amy Adams (No. 9, $22.60 returned for every $1 paid) and Kevin James (No. 10, $22.40 returned for every $1 paid).