He’s a Stanford Law alum.
His company developed a burger-flipping robot.
He was previously married and is a dad of two.
He supports Garner’s projects—out of the spotlight.
He and Garner have ‘hit a stride as a couple.’

The ‘13 Going on 30’ actress and businessman have dated on and off since 2018.

He’s a Stanford Law alum., His company developed a burger-flipping robot., He was previously married and is a dad of two., He supports Garner’s projects—out of the spotlight., He and Garner have ‘hit a stride as a couple.’

Key Points

Jennifer Garner has been dating CaliGroup CEO John Miller since 2018.
Miller is a Stanford Law alum best known for developing AI and tech-related innovations in the fast-food space.
Like Garner, who shares three kids with ex-husband Ben Affleck, Miller is a parent of two children from a previous marriage.

Jennifer Garner is enjoying a low-key love. The 13 Going on 30 star has been romantically linked to CEO John Miller since late 2018, although the pair have chosen to keep their relationship largely under wraps.

Garner and her ex-husband, actor Ben Affleck, finalized their divorce in October 2018, per People. The former couple welcomed three children: Violet, Seraphina, and Samuel. Miller also shares two children with his ex-wife, violinist Caroline Campbell.

The actress and businessman split in 2020, but reconciled sometime after. “They took a long break from dating, but Jen is very happy that they are back together,” a source told People in February 2023, adding that the couple “have a very special relationship.”

In August 2024, the couple were spotted on a date night in Los Angeles. At the time, a source told People Garner was “happy with” Miller amid news of her ex-husband’s divorce from Jennifer Lopez.

As Garner continues to actively co-parent her three kids with Affleck—even attending a Boston Red Sox game together in July 2025—Miller is reportedly fully supportive of his girlfriend’s dynamic with her ex-husband. “John has embraced Jen’s family life,” a source told People in July 2025. “He’s been patient, supportive, and deeply respectful of her dynamic with Ben and the kids.”

While neither the Family Switch actress nor the CaliGroup CEO have addressed their relationship publicly, rare snaps of the couple show them to be very much in love. Below, here’s everything we know about Jennifer Garner’s boyfriend.

He’s a Stanford Law alum.

Miller has the credentials to back up his CEO status—the Los Angeles native graduated from Stanford Law School and joined the California Bar in the Northern District of California, per his author bio.

After he graduated Order of the Coif from Stanford, the attorney served as managing editor of Nanotechnology Law & Business, an academic journal. He’s also co-authored a book and articles on policy issues in the field of nanotechnology, making him something of a tech whiz.

His company developed a burger-flipping robot.

He’s a Stanford Law alum., His company developed a burger-flipping robot., He was previously married and is a dad of two., He supports Garner’s projects—out of the spotlight., He and Garner have ‘hit a stride as a couple.’

As chairman of CaliGroup, an investment company, Miller has led his share of innovations. None are as unique as the burger-flipping robot “Flippy,” which is employed in the company’s CaliBurger restaurants and was developed by Miso Robotics, per NPR.

“We have a lab full of robots making french fries, making burgers on the grill, and all sorts of other ideas for using AI and robots to automate kitchens,” Miller said in a 2020 presentation at the RestaurantSpaces retreat in Pasadena.

Per a 2025 press release from Miso Robotices, Flippy has branched out from CaliBurger and is now operating in a variety of fast-food chains, including White Castle and Jack in the Box.

He was previously married and is a dad of two.

Before he began dating Garner in 2018, Miller tied the knot with celebrity violinist Caroline Campbell. The pair wed in 2005. Miller filed for divorce in 2011.

Like Miller, Campbell attended Stanford University, per her professional bio. As a violinist, she’s performed or recorded with music legends like Stevie Wonder, Norah Jones, Andrea Bocelli, Sting, and Rod Stewart, among others. In August 2021, she married competitive runner Christopher Estwanik, sharing the news on her Facebook.

He supports Garner’s projects—out of the spotlight.

While Miller and Garner keep a low profile when it comes to their romantic relationship, the pair do quietly show up for each other. In April 2023, People confirmed that Miller attended the premiere of her Apple TV+ limited series The Last Thing He Told Me, although he chose not to walk the red carpet.

More recently, in June 2025, the businessman was spotted sharing a kiss with Garner at a Save the Children charity event. The occasion marked the final day of a 67-day running streak Garner participated in as part of the charity’s #67Strong4Kids campaign.

Garner posted about the campaign on her Instagram, sharing in the caption of a post, “I’ve been running one mile a day for the last 67 days—just $67 can help bring a child back from the brink of starvation.” The actress has been an ambassador for the charity for 15 years after joining its board in 2014.

He and Garner have ‘hit a stride as a couple.’

Seven years into their relationship, Garner and Miller are reportedly doing “better than ever,” according to an exclusive source who spoke with People in July 2025. The unnamed insider told the outlet the actress and executive “hit a stride as a couple,” adding that “those who know them say this is the most solid and connected they’ve ever been.”