According to The Sun, the couple plans to get married next month in Los Angeles.
“They are planning to get married in LA in April. They just want it to be made legal so are happy with a registry office,” a source told the newspaper.
The publication also wrote that Kutcher plans to celebrate the event with a party for friends, later in the year, in the south of France.
Engagement rumors circulated last month when Kunis was seen wearing a diamond ring on her ring finger while out shopping.
The two stars’ reps have yet to confirm the news.