The `Two and a Half Men` actor - who split from estranged wife Demi Moore last November after he allegedly cheated on her - is said to have enjoyed several dates with Mila, who he starred with in `That `70s Show`.
According to X17 Online, the pair have been spotted together on multiple occasions and they have both spent nights at each others` houses.
On 15.04.12, Ashton and `Black Swan` star Mila spent the day furniture shopping and then enjoyed a sushi dinner at Los Angeles restaurant Asanebo, before heading back to Ashton`s Hollywood Hills home.
An onlooker at the restaurant said: "Ashton was touching Mila`s hand and Mila was all dressed up. She looked hot; this was definitely more than a dinner between friends - this was a full-on date!"
Ashton - who was married to Demi for six years - was recently linked to `S&M` singer Rihanna, although the romance was never confirmed.
Mila previously dated Macaulay Culkin for eight years but they split in 2010.