Strider, Azure, Arcadia and Seldon

Elon Musk and Shivon Zilis, an executive at his brain-chip company Neuralink, share four children: Boy-girl twins Strider and Azure, daughter Arcadia and son Seldon Lycurgus.

Zilis, a Yale graduate who specializes in machine learning and artificial intelligence, first crossed paths with Musk when she joined OpenAI (a startup he cofounded) in 2016. She is currently the director of special projects at Neuralink, another one of Musk’s companies.

As an employee of Musk’s, Zilis holds the entrepreneur in high regard, writing on X in 2020 that there was “no one I respect and admire more.” So when the Tesla founder, who has been outspoken about his concern over falling birth rates, approached Zilis with the idea of having children together via in vitro fertilization, she was on board, according to an account she shared with Walter Isaacson for his 2023 biography of Musk.

“He really wants smart people to have kids, so he encouraged me to,” Zilis told Isaacson. “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—— easy decision. I couldn’t possibly think of genes I would prefer for my children.”

Musk, who has 10 additional children with three other women, was also excited over the prospect, according to Zillis’ account. “It seemed like something that would make him very happy,” she shared with Isaacson.

As a result, Zilis followed Musk from Silicon Valley to Austin, Texas, where they welcomed twins via IVF in November 2021. Zilis and Musk have since had two more children: a daughter named Arcadia, born in February 2024, and a son named Seldon Lycurgus.

Here is everything to know about Elon Musk and Shivon Zilis’ four children together: Strider, Azure, Arcadia and Seldon.

Strider and Azure, 3

Musk secretly welcomed twins, son Strider and daughter Azure, with Zilis in November 2021. The twins are Musk’s first children with Zilis — but his ninth and tenth overall.

Strider and Azure were born just weeks before Musk welcomed his second child with Grimes in December 2021. The singer, whose real name is Claire Boucher, was reportedly unaware of the twins’ existence until months later, when Insider published court documents in July 2022 revealing Musk had fathered the children with the Neuralink project director. (Grimes later wrote on X that “communication about the twins wasn’t handled super well.”)

Musk and Zilis had filed a petition in April 2022 requesting to change their babies’ names so they would “have their father’s last name and contain their mother’s last name as part of their middle name.” A judge granted the request a month later.

The twins’ names and sexes, along with their first photo, were revealed in a September 2023 TIME article that published an excerpt from Isaacson’s biography of Musk (which was published the same month). The book itself shared the children’s full names: Strider Sekhar Sirius and Azure Astra Alice.

Since then, Zilis has continued to share occasional updates of the twins — whom she calls the “lil loves of my life” — on her X account. Most recently, in May 2025, she posted photos of Strider and Azure visiting their father at SpaceX, Musk’s space technology company.

“Taking notes. Dream big, little ones! ✨” she wrote alongside the pictures, which showed the toddlers sporting SpaceX T-shirts.

Arcadia, 1

On Feb. 28, 2024, Musk and Zilis welcomed their third child together — and his 12th overall — daughter Arcadia. The baby’s arrival was first reported by Bloomberg in June 2024, and confirmed by Musk to Page Six — though, at the time, he did not reveal the child’s name, birthdate or sex.

“As for ‘secretly fathered,’ that is also false. All our friends and family know,” Musk told Page Six in a statement. “Failure to issue a press release, which would be bizarre, does not mean ‘secret.’ ”

Zilis didn’t speak publicly about her third child until the baby’s first birthday, when she posted a tribute on X. In it, she shared their daughter’s name, Arcadia, and when she was born.

“Happy 1st birthday, darling Arcadia. Mommy loves you with all her heart,” the Neuralink executive wrote.

Seldon Lycurgus

In February 2025, Zilis announced on X that she and Musk had had a fourth baby together. In the post, Zilis wrote that she and Musk had welcomed a second son, named Seldon Lycurgus, though she did not reveal when he was born.

“Discussed with Elon and, in light of beautiful Arcadia’s birthday, we felt it was better to also just share directly about our wonderful and incredible son Seldon Lycurgus,” Zilis wrote on X on Feb. 28, 2025.

She went on to describe her youngest child as “built like a juggernaut, with a solid heart of gold.”

“Love him so much ♥️,” Zilis concluded. Musk replied to the post with a red heart emoji.