The 29-year-old beauty knocked Rihanna off the top spot to gain the coveted title and posed topless on the front cover of the November 2012 issue in just a pair of leather trousers.
Kunis also posed in sexy lingerie for the photo spread inside the publication, which hits news stands on October 8.
The Ted star and Kutcher have gone public with their romance in recent weeks, and Us Weekly reported they even went to the Kabbalah Center in NYC for a Rosh Hashanah holiday service on September 18.
Kutcher is still married to Demi Moore, although the two split a full year ago.
Kunis - who is currently filming The Angriest Man In Brooklyn - has spoken out in the past about being bullied for her unusual looks as a child.
She claimed she was made fun off because of her big eyes, big lips and big ears.
Looks like she's having the last laugh.