OpenAI Billionaire Sam Altman Lists Hawaii Compound Where He Wed Husband Oliver Mulherin for $49 Million

Billionaire AI mogul Sam Altman is preparing to part ways with his enormous Hawaii compound, putting the property on the market for the eye-watering sum of $49 million—just 18 months after he wed his longtime partner, Oliver Mulherin, on the grounds of the estate.

Altman, 40, who is the CEO of OpenAI, the company behind ChatGPT, quietly purchased the property in an off-market deal back in July 2021; however, his ownership of the extraordinary beachfront dwelling was not made public until November 2023.

Since then, Altman’s career has gone from strength to strength, thanks largely to the launch of ChatGPT in 2022, which helped OpenAI to become a major player in the tech world—while its CEO’s profile skyrocketed.

Still, the OpenAI mogul has largely tried to avoid the spotlight, at least where his personal life is concerned. His Instagram account, which has just over 5,000 followers, is private; and unlike other wealthy tech tycoons, he rarely shares details about his private affairs.

When he and Mulherin tied the knot in January 2024, the event went very much under the radar—so much so that when images from the ceremony began circulating online, many believed them to have been AI-generated, until Altman confirmed his marriage to NBC.

At the time, the AI entrepreneur neglected to share any details about the ceremony—however, the listing photos for his Hawaii compound reveal the property as the location of the intimate event, showcasing the same palm tree-filled background that featured in the images taken during Altman’s wedding.

However, palm trees are just one of the many exotic amenities on offer in and around the home, which is located in Kailua-Kona on the Big Island and sits next to a reconstruction of the temple of King Kamehamela I, the first ruler of the Kingdom of Hawaii.

Set on a staggering 21.8 acres of “secluded luxury,” the property features a total of 10 bedrooms and 11.5 bathrooms, which are split between a main residence and a guesthouse. At $49 million, the property is currently the second most expensive dwelling on the market in Hawaii.

“The estate offers exceptional privacy with a main residence, guest house, and beach bungalow, each crafted with meticulous design,” the listing, which was first reported by Forbes, crows. “Every inch is designed for relaxation, entertaining, and unwinding in style.”

During the four years that he has owned the property, which was previously owned by Microsoft co-founder Paul Allen, Altman has made many upgrades and updates, per the listing—which draws particular attention to the “advanced security systems” that have been put in place to “guarantee peace and discretion.”

Certainly, those who wish to shy away from prying eyes could happily remain behind the walls of the compound with little reason to venture outside—thanks to the many fun-filled features that the property has to offer.

Inside, the main residence boasts a movie theater, several enormous indoor/outdoor living spaces, and a sizable kitchen with ample room for guests to dine at the breakfast bar.

However, the property’s true potential really shines in its extraordinary outdoor offerings, which include a heated gunite pool—with a built-in spa—as well as a full sports court that is set up for basketball and tennis, and a private marina that has been outfitted with a man-made beach, effectively turning it into a second swimming pool.

The estate is situated on the water front, providing instant access to the beach, where many different water sports can be enjoyed, with the listing images capturing two people heading out to paddle board from the private marina.

The listing also includes an image of a helicopter landing on the grounds, revealing a special plot of flat land ideal for use as a helipad.

Additionally, there are multiple entertaining areas located within the grounds of the home, including a sheltered lanai with a large dining room table, where Altman and Mulherin were pictured dining with guests after their wedding ceremony.

“Every detail, from oceanfront views to exclusive amenities is crafted for a life of privacy and elegance,” the description notes.

“Located in one of Hawaii’s most prestigious settings, this estate embodies a blend of luxury and natural beauty. Expansive living spaces, lush outdoor areas, and sweeping views of Kailua Bay and the Pacific Ocean, create a refined island experience.”

The true size of the property is reflected at the end of the listing, which makes mention of Hawaii’s unique tax map key (TMK), a system used in the state to identify property ownership, assess taxes, and track legal boundaries.

Each TMK in the state is made up of five numbers that pinpoint the property’s exact location—however, in the case of Altman’s Hawaii estate, the property incorporates six TMKs, demonstrating its impressive size.

This does, however, mean that prospective buyers will have to take into account the sky-high taxes that are associated with ownership of the estate, with Realtor.com® records revealing that Altman’s 2025 bill alone will amount to $631,454.

It is unclear why Altman has decided to try and offload the property—however, the Hawaii compound is one of several included in his portfolio.

The tech mogul’s main residences are located in San Francisco, where he purchased three homes in January of this year for $12.8 million each, according to property records.

The three dwellings are all located next to a historic six-bedroom, seven-bathroom Russian Hill mansion that he purchased for $27 million in 2020—before later becoming embroiled in a bitter and lengthy legal battle with its developer, Greg Malin, and his company, Troon Pacific, over claims that the home was “plagued by shoddy construction.”

Altman, who filed the 2024 lawsuit via the LLC through which he purchased the 1907 home, claimed in legal documents seen by Realtor.com that Malin’s company carried out “substandard work” on the home to save money during its multiyear renovation project.

“Owner … alleges that developer skimped on competent or qualified construction managers, designers, and contractors for the development of the property,” the filing states.

The suit adds that Altman had no “prior knowledge of the rancor, poor supervision, shoddy workmanship, corner-cutting, and financial embezzlement” he believes were involved in the project when he purchased the home.

Altman’s LLC “entered into negotiations to purchase what it believed to be a beautiful, luxury home in San Francisco,” it goes on. “When first put on the market, it was reported to be the most expensive home listing in San Francisco history, and it seemed obvious why.”

The filing then calls attention to the home’s most appealing amenities, including “stunning views,” floor-to-ceiling glass doors that provide an indoor-outdoor setting, an elevator, a garden with 100-year-old olive trees, a historic cottage, and an infinity pool that overlooks downtown San Francisco.

However, Altman’s lawyers claim that, after buying the home, which was described as a “lemon” in the filing, he discovered a wide range of “pervasive defects,” including issues with drainage, plumbing, waterproofing, and sewer systems.

The lawsuit claims that repairs to the home would cost more than $4 million—and notes that the LLC connected to Altman was seeking unspecified damages from Malin and Troon Pacific, as well as interest and legal fees.

Altman’s lawsuit is ongoing—however, it appears that he plans to hold on to the property and potentially expand it with the purchase of the three adjacent dwellings, which were all bought together for a total of $38.5 million, as first reported by The Real Deal.

The three homes are all registered to the same LLC, which is managed by Altman’s cousin, Jennifer Serralta, who also oversees the LLCs connected to his other property purchases.

Much like the OpenAI CEO’s original Russian Hill home, the properties were all built in the early 1900s and had previously been purchased together to form a large compound by their previous owners in 1994, records indicate.

When he is not spending time in San Francisco, however, Altman can be found enjoying time at his stunning ranch in Napa, CA, where—he previously told the New York Times—he and Mulherin spend most of their weekends.

Altman invited a Times reporter, Cade Metz, to visit the home in 2023, with the resulting article noting that the 25-year-old home had been remodeled to “look both folksy and contemporary.”

The report noted that Altman, who is a vegetarian, and his then-partner were raising beef cattle on the land surrounding the home, which was tended to by farmhands, who also grew wine grapes on the property.

According to records, the ranch—which spans a staggering 950 acres—was purchased for $15.7 million in 2020, having initially been listed for $25.5 million.

Property records show that the ranch, named Green Valley Ranch, was purchased through an LLC that Altman’s cousin, Serralta, is also the manager of.

At the time of the sale, reports revealed that the ranch had previously been owned by a group of eight men, who had used the property “communally” for 42 years.

One of those men, Hollywood lighting designer Bob Dickinson, told the CT Post that the buyer, who had “asked to remain nameless,” had a “complete passion for the land.”

“This little postage stamp of indigenous undisturbed California, it’s hard to explain how marvelous it is to live where there are still river otters on your property and oaks that are centuries old,” said Dickinson.

“He gets it. He’s enthusiastic about it. He’s not a group like we were, but he has a very close family and I think his motivation is to make it the same kind of community experience with his family and friends.”

The original listing noted that the ranch was made up of nine parcels of land that were home to five “unique residences”: the main ranch house, a terra guesthouse, a meadow house, a “Palladian-inspired lake house,” and a “charming artist house.”