Mila Kunis and Ashton Kutcher have made their official red carpet debut as a couple.

Ashton Kutcher and MIla Kunis at Breakthrough Prize Awards

Ashton Kutcher and MIla Kunis at Breakthrough Prize Awards

The pair have been together for five years and they married in July 2015 but have never stepped out together to pose for the cameras at a celebrity event as a pair until now.

Mila, 34, and Ashton, 39, laughed as they stood with their arms around each other on the red carpet at the Breakthrough Prize Awards at the NASA Ames Research Centre in Mountain View, California on Sunday night (03.12.17).

The couple - who are parents to three-year-old daughter Wyatt and 12-month-old son Dimitri - met on the set of 'That 70s Show' in 1998 and became close friends. But they did not begin dating until April 2012.

They last walked the red carpet together 17 years ago with the cast of the hit sitcom long before they were an item.

'A Bad Moms Christmas' star Mila and 'Two and a Half Men' heartthrob Ashton played Jackie and Kelso in the long-running period comedy. Mila has revealed she even shared her first kiss with Ashton when their characters were dating on the show.

Mila recently spoke about how incredibly "grateful" they are to now have a family together and how much they both wanted to have kids.

She said: "I have tiny little humans. Ashton and I wanted kids so bad; we were so ready to be parents. We were able to have this little family the way we wanted, and I'm so grateful for it and it's the one thing that I can't control. That's where my vulnerability is. My job, it comes and goes. You don't get a job, you get a job, you don't get a job. Your kids, you just want one thing."