Elon Musk has said people should have as many children as they feasibly can for the good of the planet.

Hence the SpaceX founder becoming the poster billionaire for his own cause.

The 52-year-old quietly welcomed his 12th child and third with 38-year-old Shivon Zilis earlier this year, confirming as much to Page Six on June 23.

"People are going to have to revive the idea of having children as a kind of social duty," Musk said in a 2014 interview, per biographer Walter Isaacson. "Otherwise civilization will just die."

That brand of charm may not be for everybody, but the thrice-married (twice to the same woman) Tesla CEO has enjoyed a robust romantic life in the course of becoming a prolific procreator—though one circumstance hasn't necessarily been required to lead to the other. 

"He really wants smart people to have kids, so he encouraged me to," Zilis told Isaacson for his 2023 book on the man frequently atop Forbes' real-time richest-person-alive list. "If the choice is between an anonymous sperm donor or doing it with the person you admire most in the world, for me that was a pretty f--king easy decision. I couldn't possibly think of genes I would prefer for my children."

Not least, she added, "It seemed like something that would make him very happy."

But what else makes Zilis tick, you ask? Here's more to know about the tech executive who's had three babies with Musk:

Who is Shivon Zilis?

Zilis was born Feb. 8, 1986, in Markham, Ontario, to mom Sharda, who's originally from India, and dad Richard of Canada.

Speaking of her heritage, Zilis told USA Today in 2015 that she "pretty much turned out white," but attributed her big eyes to her Punjabi side. 

She played ice hockey at Yale before graduating in 2008 with degrees in economics and philosophy.

Zilis credited being a goalie for helping her develop some of the skills she later utilized in the fast-paced tech world, so much of which runs on being able to predict what consumers are going to want years down the road.

"The goalie gets to watch the play unfold from a bit of a distance so you get a unique macro level versus always being in the thick of it," she told the Financial Post in 2015. "The real art of goaltending is being able to get a good read on the players and predict what he/she is going to do." 

What does Shivon Zilis do?

She kicked off her career working for IBM in New York, focusing on micro-finance initiatives in developing countries—and furthering her interest in artificial intelligence.

In 2012 she cofounded San Francisco-based Bloomberg Beta, a $75 million venture capital fund investing in early-stage startups that focused on machine intelligence, which Zilis correctly envisioned would eventually affect countless industries.

"I always knew that stuff was going to happen before it happened," she told USA Today. Still, she called herself an "unsexy investor," more inclined to support an agricultural-tech endeavor than a buzzier company like Snapchat. 

Forbes included her in its "30 Under 30: Top Young Investors of Venture Capital" list in 2015—which Zilis called "a pretty delightful surprise."

Musk cofounded OpenAI in 2015 and reportedly met Zilis when she did consulting work for the ChatGPT creator.

In 2017, Zilis joined Tesla—where Musk was an early investor and has been CEO since 2008—as a project director for its Autopilot product and chip design team.

Musk left OpenAI in 2018, while Zilis remained on the board until March 2023. She is currently director of operations and special projects at Neuralink, which Musk started in 2016.

What is Shivon Zilis' relationship with Elon Musk?

Zilis has acknowledged that the owner of the company she works for has his issues, but she's gone to bat for Musk as a humanitarian and visionary.

"No one's perfect but I've never met anyone who goes through more personal pain to fight for an inspiring future for humanity— and has done so tirelessly for decades," Zilis tweeted about Musk in May 2020 (two years before he bought Twitter and turned it into X). "Everyone's entitled to their opinion but mine is that there's no one I respect and admire more."

Zilis told Musk biographer Isaacson that she "learned more unique lessons from Elon per minute than any other human I've met. It would be dumb to not spend some of your life with such a person."

Hence her decision to relocate from Silicon Valley to Austin, Texas, as Musk did and then have children with him, conceived via IVF. (Zilis acknowledged having "the motherhood bug super hard" but wasn't interested in getting married.)

They welcomed twins Strider Sekhar Sirius and Azure Astra Alice in November 2021—the expansion of Musk's family not known until the following July, when they filed paperwork in Texas to legally change the kids' last name from hers to his.

Zilis said that the name change was spurred by Musk's estrangement from his daughter Vivian Jenna, one of his five surviving children with ex-wife Justine Wilson. (Son Nevada Alexander died of SIDS when he was 10 weeks old.)

"When Jenna deleted 'Musk' from her name," Zilis explained, "he was just really sad. And he asked me, 'Hey, would you be open to our twins taking my name?'"

Zilis didn't expect Musk to play a traditional father role in the raising of the twins—"because the dude's got a lot going on," she told Isaacson—but he would stay at her house at least once a week and was surprisingly doting.

"There's just some stuff he can't do because he's emotionally hardwired a bit differently," she explained. "But when he comes in, they light up and have eyes only for him, which lights him up as well."

Is Shivon Zilis friends with Elon Musk's ex Grimes?

Once Zilis moved to Austin, she was part of a social circle that included Musk and his now-ex-partner Grimes, with whom he also shares sons X Æ A-Xii (X for short), 4, and Techno "Tau" Mechanicus, 2, and daughter Exa Dark Sideræl (also known as Y), 2.

According to Isaacson, the singer considered Zilis a friend and occasionally tried to matchmake for her. 

Musk's twins with Zilis arrived a few weeks before Exa was born through a surrogate in December 2021, three months after Musk and Grimes "semi-separated," as he put it in a tweet.

"It's mostly that my work at SpaceX and Tesla requires me to be primarily in Texas or traveling overseas and her work is primarily in LA," Musk wrote. "She's staying with me now and Baby X is in the adjacent room."

As for Grimes' decision to have a second child with Musk (via surrogate following her tough first pregnancy), she told Isaacson, "I really wanted him to have a daughter so bad." 

Grimes and Musk reunited but had broken up again by March 2022 while their third child was on the way. Tau was born via surrogacy in June 2022.

Meanwhile, Grimes didn't know that Musk was the father of Zilis' babies until the rest of the world found out from the published court filing in July 2022 and, according to Isaacson, was "outraged."

Musk acknowledged the eyebrow-raising news that he had children with someone who worked at his companies by tweeting, "Doing my best to help the underpopulation crisis. A collapsing birth rate is the biggest danger civilization faces by far."

Where is Shivon Zilis now?

Zilis lives in Austin with the twins and her months-old third child with Musk, whose name and sex have not been publicly shared.

"All our friends and family know," he told Page Six June 23. "Failure to issue a press release, which would be bizarre, does not mean 'secret.'"

And Zilis remains onboard with his myriad visions.

"It's been one of the most meaningful friendships of my life, by far," Zilis told Isaacson of her kids' father. "Soon after I met him I said, 'I hope we're friends for life."

As Musk quipped during a dinner with several NASA directors in February 2022, barely two months removed from the birth of his twins with Zilis and then his daughter with Grimes, "Among my friends, the average number of kids is one. Some have zero. I try to set a good example." 

For a full breakdown of Musk's family, relationships and the 12 children that followed, read on…

Maye was born in Saskatchewan, Canada and emigrated with her parents to Pretoria, South Africa in 1950, when she was 7. She and Elon's father, Errol Musk, split in 1979.

After Elon moved to Canada at age 17, Maye obtained Canadian citizenship by birthright and moved there too. There, she established a dietician practice and became President of the Consulting Dieticians of Canada. She also worked as a model.

In 2019, after Elon sold his company Zip2 for more than $300 million, he bought his mom an apartment in New York City, where she lived for 13 years and continued her modeling career after being signed to the IMG Models agency.

"I brought my children up like my parents brought us up when we were young: to be independent, kind, honest, considerate and polite," Maye wrote in an essay for CNBC. "I taught them the importance of working hard and doing good things."

Elon's father is an engineer and like Elon, was born in South Africa.

Though Errol said in a 2015 Forbes interview that he used to often take his kids on trips overseas—"Their mother and I split up when they were quite young and the kids stayed with me. I took them all over the world."—his relationship with Elon isn't picture perfect.

In an emotional 2017 Rolling Stone interview, Elon criticized his father and talked about his upbringing, saying that after his parents split, he moved in with his dad, which, he said, "was not a good idea."

However, Errol told Rolling Stone, "I love my children and would readily do whatever for them."

Following his divorce from Maye, Errol married Heide, whose daughter Jana Bezuidenhout was 4 years old at the time. Errol and Heide went on to have two daughters together before they, too, broke up. 

Years later, Jana reached out to Errol following a breakup of her own. "We were lonely, lost people," Errol explained in a 2018 interview with The Sunday Times. "One thing led to another—you can call it God's plan or nature's plan."

Either way, the duo became romantic and welcomed son Elliott in 2017 and then a baby girl in 2019. As Errol put it to The Sun, "The only thing we are on Earth for is to reproduce. If I could have another child I would. I can't see any reason not to."

Kimbal, born in 1972, is a restauranteur and the founder of The Kitchen, a collective of five restaurants that source directly from local farmers. He also runs a non-profit, Big-Green, that has built 200 learning gardens in schools across the U.S., the outlet said.

Tosca, born in 1974, is a filmmaker. In 2017, she founded Passionflix, a female-focused streaming service that targets the billion-dollar romance novel industry. 

Elon and Canadian-born Justine, his college sweetheart from Queen's University in Ontario, married in 2000. In a 2010 article she penned for Marie Claire, titled I Was a Starter Wife: Inside America's Messiest Divorce, Justine said that while dancing at their wedding reception, Elon told her, "I am the alpha in this marriage."

"I shrugged it off," Wilson wrote, "just as I would later shrug off signing the postnuptial agreement, but as time went on, I learned that he was serious."

The two faced an unthinkable tragedy when their baby boy Nevada Alexander died at 10 weeks from Sudden Infant Death Syndrome (SIDS). "Nevada went down for a nap, placed on his back as always, and stopped breathing," Justine wrote in her article.

The couple pursued IVF to conceive again and went on to welcome five more kids: Twins Vivian and Griffin and triplets Kai, Saxon and Damian. 

In 2008, Elon filed for divorce.

In a July 2022 snap, Elon revealed he took his oldest sons to meet Pope Francis. While he was honored to meet the head of the Catholic church, Elon added of his 'fit, "My suit is tragic." 

That same year, Elon's daughter Vivian filed a petition to change her full name in accordance with her new gender identity, writing, "I no longer live with or wish to be related to my biological father in any way, shape or form."

Elon and Talulah—who starred on HBO's Westworld—married in 2010. "It all happened very fast," she told CBS News. "We were engaged after, I think, two weeks of knowing each other."

The two divorced in 2012, then remarried a year later before divorcing again in 2016. In June 2024, she wed Love Actually alum Thomas Brodie-Sangster.

Elon and Amber went public with their romance in early 2017, a year after she filed for divorce from Johnny Depp and Elon ended his (second) marriage to Talulah. Though their relationship didn't last long.

"I just broke up with my girlfriend," Elon told Rolling Stone at the time. "I was really in love, and it hurt bad...Well, she broke up with me more than I broke up with her, I think."

Elon and the singer dated on-and-off for four years, starting in 2018. In September 2021, Elon told Page Six that he and Grimes "are, I'd say, probably semi-separated," adding, "It's mostly that my work at SpaceX and Tesla requires me to be primarily in Texas or traveling overseas and her work is primarily in LA. She's staying with me now and Baby X is in the adjacent room."

However, in March 2022, she told Vanity Fair that they "live in separate houses" and are "best friends."

She later tweeted, "Me and E have broken up *again* since the writing of this article haha, but he's my best friend and the love of my life, and my life and art are forever dedicated to The Mission now." 

When news broke in September 2023 that the couple share three children together, the "Crystal Ball" singer confirmed that, yes, their most recent addition Techno Mechanicus had joined son X Æ A-12, 3, and daughter Exa Dark Sideræl.

In 2020, Elon and Grimes welcomed their first child together, a son. They soon modified the spelling of his name in order to meet California's legal guidelines, which only permit letters from the English alphabet. Switching over to roman numerals, the parents agreed to spell his name, X Æ A-Xii.

"X, the unknown variable," Grimes explained on Twitter. "Æ, my elven spelling of Ai (love &/or Artificial intelligence) A-12 = precursor to SR-17 (our favorite aircraft). No weapons, no defenses, just speed. Great in battle, but non-violent." 

Grimes continued, "A=Archangel, my favorite song" adding a rat and sword emoji. "Metal rat."

In her 2022 Vanity Fair interview, Grimes revealed she and Elon privately welcomed a baby girl via surrogacy.

"Exa is a reference to the supercomputing term exaFLOPS (the ability to perform 1 quintillion floating-point operations per second)," she said. "Dark, meanwhile, is the unknown. People fear it but truly it's the absence of photons. Dark matter is the beautiful mystery of our universe.'"

Sideræl—pronounced "sigh-deer-ee-el"—is, according to mom, "the true time of the universe, star time, deep space time, not our relative earth time," and a nod to her favorite Lord of the Rings character, Galadriel, who "chooses to abdicate the ring."

A year later, the New York Times' review of Walter Isaacson's biography Elon Musk confirmed that Elon and Grimes share three children. The on-again, off-again couple at one point welcomed a child named Techno Mechanicus, nicknamed Tau, a report Grimes confirmed soon after.

"I wish I could show u how cute little Techno is," she wrote on X, "but my priority rn is keeping my babies out of the public eye, Plz respect that at this time."

In 2022, Business Insider published court documents that stated Elon welcomed twins in November 2021 with Neuralink executive Shivon Zilis. The babies were born in Austin, Texas, where he lives.

He also seemingly weighed in on the report on X, writing, "Doing my best to help the underpopulation crisis. A collapsing birth rate is the biggest danger civilization faces by far."

"Mark my words," he added, "they are sadly true."

In September 2023, a TIME magazine cover story revealed that their twins were named Strider and Azure.

In 2024, Elon and Zilis welcomed their third baby together. The billionaire confirmed the news in June 2024, telling Page Six, "All our friends and family know," adding, "Failure to issue a press release, which would be bizarre, does not mean 'secret.'"