12 Celebrity Ex-Couples You Never Knew Dated: From Chris Pratt and Emily VanCamp to Ryan Gosling and Sandra Bullock

Ashton Kutcher and January Jones started dating when they were in their 20s, but they broke up years before he married Demi Moore in 2005.

RadarOnline.com shared an excerpt from Moore's memoir, Inside Out, in which she revealed Kutcher suspected Jones had an affair with Bruce Willis.

Chris Pratt and Emily VanCamp appeared on Everwood as siblings Bright and Amy Abbott. They started dating in 2004 while working on the project but called it quits in 2007.

In an episode of the "Armchair Expert" podcast, Dax Shepard confirmed he once dated Ashley Olsen after meeting at a party.

"When we were dating, it was when she was putting all her energy and focus into launching that in a big way," he said. "So, I was able to see her meet with design teams and, like, run her s--- and she handled her B, and it's very impressive."

Rashida Jones joined the cast of The Office for a short time. But before that, she dated John Krasinski from 2005 to 2006.

"He's one of my closest friends," Jones said in 2006. "He was incredibly supportive of me getting this job, and for the most part, if you go out with somebody and it doesn't work out, there's always a reason why you liked the person to begin with."

Liam Neeson and Helen Mirren, who have seven seven-year age gap, dated in the 1980s after meeting on the set of Excalibur. Although they broke up in 1985, they have remained open about their relationship.

"I should be so lucky and be honored to have spent three or four years with that lady," Neeson told ET Canada. "She's really something else."

Macaulay Culkin and Mila Kunis were an item from 2002 to 2011, though they did not share anything about their romance at the time.

But years after their split, Kunis told Shepard she had a "horrible, horrible breakup" with the Home Alone star.

From being friends, Matthew Perry and Julia Roberts became lovers while shooting an episode for Friends. They broke up six months later.

When Perry died, Roberts shared a heartbreaking statement during her interview with ET.

"The sudden passing of anybody so young is heartbreaking," Roberts said. "I think that, you know, it just helps all of us just appreciate what we have and to keep going in a positive way as best we can."

Nicole Kidman addressed her relationship with Lenny Kravitz for the first time during a press tour for Big Little Lies.

"I knew Zoe [Kravitz] because I was engaged to her father," she said. "It's all in the family! I love Lenny. He's a great guy."

The pair, who broke up in 2003, also got engaged.

Robert Downey Jr. and Sarah Jessica Parker moved in together after a few weeks of dating in the 1980s. However, the Iron Man star was already struggling with substance abuse, which eventually led to their breakup.

"I liked to drink, and I had a drug problem, and that didn't jibe with Sarah Jessica, because it is the furthest thing from what she is. She provided me a home and understanding. She tried to help me. She was so miffed when I didn't get my act together," Downey Jr. told Parade in 2008.

Despite their 16-year age gap, Ryan Gosling and Sandra Bullock's relationship bloomed but remained the details private. They dated for two years before they split amicably in 2003.

Before marrying Jada Pinkett Smith, Will Smith dated his The Fresh Prince of Bel-Air costar Tyra Banks for a year between 1993 and 1994. Although they went their separate ways, the pair have remained friends over the past years.

Winona Ryder and Matt Damon met through Gwyneth Paltrow in 1997. They continued seeing each other until they broke up after marking their last public appearance at the 2000 Golden Globe Awards.