Last week, the Alias actress, 51, was all-smiles as she chatted to her boyfriend through his car window before giving him a smooch, as per British media.

Before that, in early November, they were seen walking hand in hand in a rare public outing in Santa Monica, Los Angeles, per People magazine.

Unlike Garner’s ex-husband Ben Affleck and his new wife Jennifer Lopez – who rekindled their romance very publicly in 2021 – the 13 Going on 30 star and her low-key man have a more hush-hush romance that’s so far been shielded from the public.

Jennifer Garner with Hollywood pal Reese Witherspoon in 2017. Photo: Handout

Here’s what we know about Garner’s lesser-known BF, who she’s been dating on and off since 2018:

What does John Miller do for a living?

Jennifer Garner’s new partner is a tech entrepreneur. Photo: @jennifer.garner/Instagram

According to Town & Country Mag, Miller is an inventor and an entrepreneur.

Born in 1978 and raised in Los Angeles, Miller studied economics at the University of Redlands, in California, and later got a law degree from Stanford, per the source.

His bio on start-up founder platform F6S states that Miller is an “inventor and entrepreneur focused on how new technologies will impact the retail and restaurant industries.” It also lists that he worked at Arrowhead Pharmaceuticals and was a managing editor of Nanotechnology Law & Business.

Jennifer Garner has been married twice but according to sources isn’t in a rush to do so again. Photo: @jennifer.garner/Instagram

He is now the founder of Cali Group, which owns CaliBurger. “We really think of ourselves as a technology company that happens to sell cheeseburgers,” Miller said in 2017.

He has an on-off relationship with Jennifer Garner

Garner and Miller started dating in 2018, split up in 2020 and got back together in 2021, according to US Weekly. In the time that they were apart, Garner was spotted on what appeared to be dates with Bradley Cooper, including a Malibu beach outing. It turned out to be just rumours though, as sources later denied that they were dating.

Miller was married to a violinist

Caroline Campbell is John Miller’s ex-wife. Photo: @carolinetheviolinist/Instagram

Like Garner, Miller has been married before. Per Town & Country Mag, he tied the knot with violinist Caroline Campbell back in 2005, and filed for divorce six years later. They ended up reconciling in 2012, before filing the divorce papers again two years later. It wasn’t until November 2018 when the split was officially settled.

Does John Miller have kids?

Jennifer Garner still does the Hollywood thing from time to time, but her new partner isn’t so big on red carpet appearances. Photo: @jennifer.garner/Instagram

Miller has two children from his previous marriage to Caroline Campbell.

Per Town & Country Mag, they have a daughter and a son together: Violet and Quest, though not much is known about the pair.

Garner, meanwhile, shares three children with Ben Affleck: Violet, Seraphina and Samuel. An Us Weekly article in April 2022 reported that Miller’s children met Garner’s in a “casual and easy” setting.

Who has Jennifer Garner been married to?

Jennifer Garner, left, and Ben Affleck at the Oscars in 2013 while they were still together. Photo: AP

Jennifer Garner has been married twice.

She was married to first husband Scott Foley – her co-star from TV show Felicity – from 2000 to 2004. Not long after splitting from Foley, Garner walked down the aisle again, this time with her Daredevil and Pearl Harbor colleague Ben Affleck, per Parade. They were together from 2005 until 2018, but had already gone their separate ways in 2015, states the source.

Although she’s clearly smitten with her new beau, it seems Jen isn’t rushing to get married again any time soon, according to an interview with a source close to the couple in Us Weekly. “They’re happier being a regular, under-the-radar couple and don’t need anyone else’s validation to know they’re meant to be together,” they explained.

Where is Jennifer Garner’s ex-husband Ben Affleck now?

Ben Affleck and Jennifer Lopez are a more public couple than Jennifer Garner and John Miller. Photo: GC Images

Affleck, 51, also found love again after his divorce from Garner. He married pop superstar J. Lo last year, and as a result has added more children to his blended family. Per Hello!, Affleck is considered stepdad to Lopez’s twins, Emme and Max, both 15.

Jennifer Lopez and husband Ben Affleck hope to be great parents to each other’s children from previous marriages. Photo: @jlo/Instagram

The “Jenny from the Block” singer told Vogue: “They [the children] have so many feelings. They’re teens. But it’s going really well so far.” She added, “What I hope to cultivate with our family is that [Affleck’s] kids have a new ally in me and my kids have a new ally in him, someone who really loves and cares about them but can have a different perspective and help me see things that I can’t see with my kids because I’m so emotionally tied up.”