A source previously told PEOPLE the pair “like to date out of the spotlight”

The couple was spotted holding hands while on a walk in Santa Monica, California, on Saturday, wearing coordinating gray outfits.

Garner, who next stars in the holiday film Family Switch on Netflix, first connected with Miller, chairman and CEO of Cali Group, back in 2018 shortly before she finalized her divorce from Ben Affleck.

She shares three kids with Affleck, and Miller has two children with his ex-wife, violinist Caroline Campbell.

 Jennifer Garner and John Miller’s Relationship Timeline

Jennifer Garner and John Miller on Nov. 4, 2023.

By 2020, it seemed Garner and Miller had gone their separate ways, but the following year they appeared back on when they were spotted spending time together on multiple outings.

A source told PEOPLE in February that the pair “like to date out of the spotlight” and they are having “a lot of fun” together.

The insider added at the time that Garner and Miller had gotten back together a year ago after taking a break from dating.

“They have a very special relationship. It’s never been the easiest one though since they both have families,” the source said. “They took a long break from dating, but Jen is very happy that they are back together.”

Jennifer Garner at the Los Angeles premiere of “The Last Thing He Told Me” on April 13, 2023.

In April, Miller supported Garner at the Los Angeles premiere of her series The Last Thing He Told Me, though they did not walk the red carpet together.

Garner, 51, told PEOPLE back in March 2021 that the idea of getting married again wasn’t an immediate thought.

“I don’t know. I’m so far from it. And I don’t know that marriage would need to be a part… I mean I definitely don’t think that I’ll be single forever,” she said at the time. “But this is not the time. I don’t need to complicate it. I’m good.”