The 'Friends With Benefits' star took the lead with her raunchy topless cover of the US version of Esquire magazine which saw her being named Sexiest Woman Alive by the Sun.
Mila received 20 percent of the 38,670 votes cast in the online survey, fighting off competition from the likes of Kim Kardashian, Pamela Anderson and Tulisa Contostavlos.
The actress appeared on the front of the magazine wearing nothing but a pair of faux leather trousers, the Sun reported.
The 29-year-old actress just managed to slip her victory past glamour girl-turned-body builder Jodie Marsh - who came in second place with 18 percent after campaigning for votes on Twitter.
She was followed by Kelly Brook in third place with 9 percent.
Rihanna and Coco Austin who completed the Top Five with 7 percent each.
Kunis has spoken out about being bullied for her unusual looks as a child in the past. She claimed she was made fun of because of her big eyes, big lips and big ears.
The actress, who rose to fame on 'That 70's Show' at the age of 14, says being the daughter of poor immigrants from Ukraine has helped her develop the thick skin she needs to survive in Hollywood.
"You build it up. My dad always said I have a really good backbone. I grew up in LA, I didn't grow up wealthy or even middle class, we were pretty poor and you learn how life works very quickly," Contactmusic quoted her as saying.