Who Is Nathan Andersen? The Truth About A.J. Cook’s Husband
If you watch Criminal Minds: Evolution on Paramount+, you know A.J. Cook as the sharp, fearless Jennifer “JJ” Jareau. But in May 2026, a growing number of fans are searching not for the actress but for the man behind her: Nathan Andersen. He is an entrepreneur, a fashion designer, an outdoor adventurer, and a cancer survivor. Most of all, he is a man who quietly built a full and meaningful life while the world watched his wife become a TV icon. This article covers everything about Nathan Andersen in one place.
Nathan Andersen is an American entrepreneur and co-founder of the minimalist clothing brand Walter Sky. He has been married to actress A.J. Cook since August 2001. He survived thyroid cancer, raised two sons who both appeared on Criminal Minds, and built a business from scratch based on his love of travel and the outdoors. Here is his complete story.
Who Is Nathan Andersen?
Nathan Andersen is an American entrepreneur and fashion designer born on May 25, 1978. He is best known publicly as the husband of Canadian actress A.J. Cook, but he built his own career long before he was known by that label. He is the co-founder of Walter Sky, a minimalist outdoor clothing brand he launched with his brother Wesley Andersen. He is also a thyroid cancer survivor and a devoted father of two sons.
Nathan Andersen was born on May 25, 1978, in the United States. He attended college in Utah, where he enrolled in a film class alongside A.J. Cook. That film class was the setting where their relationship began, and it laid the foundation for their lifelong partnership.
He grew up in a family that valued sport, adventure, and ambition. His father was an athlete who later became a businessman. His mother was a skier and a natural thrill-seeker. That environment shaped Nathan into the kind of person who would later climb mountains, design clothes for adventurers, and quietly build a life that does not depend on anyone else’s fame.
Nathan Andersen Quick Facts
| Detail | Answer |
| Full Name | Nathan Andersen |
| Date of Birth | May 25, 1978 |
| Age (May 2026) | 47 years old |
| Nationality | American |
| Education | Utah Valley University (Film & Communications) |
| Wife | A.J. Cook (married August 3, 2001) |
| Sons | Mekhai Allan Andersen, Phoenix Sky Andersen |
| Business | Walter Sky (co-founded with brother Wesley) |
| Cancer Survivor | Yes, thyroid cancer, cancer-free since 2019 |
| Net Worth | Approx. $4 million |
Nathan Andersen’s Early Life and Family Background
Nathan Andersen grew up in an active, ambitious household. His father moved from athletics into entrepreneurship, showing Nathan that you do not have to stay in one lane. His mother’s love of skiing and high-risk outdoor activity gave Nathan an early comfort with physical challenge and adventure.
Nathan Andersen has a brother named Wesley Andersen. Wesley later became his co-founder at Walter Sky. Even Nathan’s parents’ identities are not widely known, as he is a deeply private individual who has not shared much of this information publicly.
As a child, Nathan climbed trees, collected things, and explored wherever he could. That restless curiosity never left him. It eventually became the exact personality that drives Walter Sky’s entire identity as a brand. He grew up believing that quality beats quantity, that nature beats noise, and that doing something well once is better than doing many things halfway.
Nathan Andersen’s Education at Utah Valley University
Nathan Andersen studied film and communications at Utah Valley University (UVU) in Salt Lake City, Utah. That course of study put him in the same room as A.J. Cook, who was also studying there at the time.
He studied film and communications at Utah Valley University (UVU) in Salt Lake City, Utah. It was there that he met A.J. Cook in a film class, and their relationship grew stronger when A.J. moved to Salt Lake City.
After university, Nathan worked in the entertainment industry for a short time. He quickly realized that Hollywood’s culture of attention and spectacle did not suit him. He stepped away, joined a startup, and spent nearly a decade building experience in business, product development, and leadership. That decade of quiet, unglamorous work laid the foundation for everything he later built.
Who Is Nathan Andersen?
Nathan Andersen is an American entrepreneur and fashion designer born on May 25, 1978. He is the husband of actress A.J. Cook and the co-founder of Walter Sky, a minimalist outdoor clothing brand launched with his brother Wesley Andersen. He is also a thyroid cancer survivor who publicly announced he was cancer-free in September 2019. He has two sons: Mekhai Allan Andersen and Phoenix Sky Andersen.
Nathan Andersen and A.J. Cook: Their Love Story
Nathan Andersen and A.J. Cook met in a film class at Utah Valley University in the late 1990s. They started as friends, then became a couple as their shared creative interests and similar values pulled them closer.
Nathan Andersen and A.J. Cook have been married since August 2001. That makes their marriage over 24 years long as of May 2026. They have been together through the early years of her acting career, the rise of Criminal Minds, her temporary firing from the show in 2010, her return, his cancer diagnosis and recovery, and the launch of his clothing business.
How They Have Kept It Together for Over Two Decades
What stands out about Nathan Andersen and A.J. Cook is how consistently private they have kept their relationship. You will not find constant red carpet appearances, public arguments played out in interviews, or social media fights. Nathan is not a celebrity husband who uses his wife’s profile to build his own. He shows up to events when it matters, stands next to her with obvious warmth, and then goes back to building his business and raising his sons.
A.J. Cook has been equally respectful of that dynamic. In interviews about her character, JJ’s marriage on Criminal Minds, she often talks about how her real life has informed her performance. That speaks to how deeply personal their bond is, even when she expresses it through fiction.
Walter Sky: Nathan Andersen’s Clothing Brand
Walter Sky is Nathan Andersen’s most publicly traceable achievement. He co-founded it with his brother Wesley Andersen, and the brand reflects everything Nathan values: simplicity, durability, function, and freedom.
Founder Nathan Andersen and co-founder Wes Andersen simply wanted a wardrobe that transcended traditional limitations in countless environments and numerous climates, but they couldn’t find it on the market. After years of tailoring his own garments, Nathan set out with a kernel of self-driven inspiration. Over the next several years, digging in with the most cutting-edge fabric mills, he engineered a small collection that achieved performance and style. Odor-resistant, strong enough to hold up in abrasive environments, and minimally attractive, each piece passed its field test one by one.
What Walter Sky Actually Sells
Walter Sky makes a deliberately limited collection of clothing. The brand is built around the idea that a small wardrobe of high-quality, versatile pieces is better than a large wardrobe of average ones. Each piece works in multiple environments, from a hiking trail to a city meeting.
After navigating four years of intricate details for an ironically minimalist brand, Nathan described the launch as bringing “everything,” including excitement, nerves, and genuine terror about whether the brand would resonate with people.
Together with his co-founder and brother Wes Andersen, Nathan embarked on a quest to redefine what it means to have a versatile, high-performance wardrobe. Frustrated by the limitations of conventional clothing and driven by a personal quest for the perfect garment, Nathan turned his vision into reality.
The brand took four years of development before it launched. Nathan was told “no” many times by fabric mills, retailers, and industry contacts who did not understand the minimalist angle. He did not stop. Walter Sky now has a loyal following among travelers, outdoor enthusiasts, and people who value clothing that functions without showing off.
Nathan Andersen’s Cancer Battle and Recovery
The most personal chapter of Nathan Andersen’s public story is his fight with thyroid cancer. He was diagnosed at some point before 2019, but he and A.J. Cook kept the diagnosis completely private while he went through treatment.
He posted a photo on Instagram showing a scar on his neck. In the caption, he wrote that he was cancer-free. He did not share all the details, but people quickly understood that he had been fighting thyroid cancer. Many people who had also battled cancer left kind messages. Some even showed their own scars and said they understood what he went through.
A.J. Cook posted on Instagram: “It’s been a hell of a year @nathanandy. I know you hate when I get all sentimental but cancer picked the wrong guy to mess with. You won, baby! You’re cancer-free. It’s like the weight of the world has been lifted.”
According to a March 2024 study published in the International Journal of Environmental Research and Public Health by researchers at the University of Hawaiʻi Cancer Center, the US five-year survival rate after a thyroid cancer diagnosis is over 95%. Nathan Andersen’s recovery, while deeply personal and difficult, placed him within a category where the medical odds were strongly in his favor. His public openness about being cancer-free in September 2019 gave hope to fans who had been through similar experiences.
How A.J. Cook Used the Experience in Criminal Minds: Evolution
Cook and Andersen kept the diagnosis and treatment private, but in 2019, Nathan revealed on Instagram that he was cancer-free. A.J. Cook later spoke to Good Housekeeping about how the experience inspired a cancer scare storyline for her on-screen husband, Will, in Criminal Minds: Evolution. “Some things happened, and we had to sort of pivot with that storyline,” she said.
That detail alone says something powerful about their relationship. A real health crisis that they faced privately ended up shaping a major plot line in a show watched by millions. The line between Nathan Andersen’s real life and A.J. Cook’s on-screen life is genuinely thin in ways that most viewers never realize.
Read more: Kelly Tisdale: The Independent Woman Behind the Shrek Star
Nathan Andersen’s Sons: Mekhai and Phoenix
Nathan Andersen and A.J. Cook have two sons. Their names are Mekhai Allan Andersen and Phoenix Sky Andersen. Mekhai was born in 2008. Phoenix was born in 2015.
Both boys have appeared on Criminal Minds and Criminal Minds: Evolution, playing the children of A.J. Cook’s character, JJ. Mekhai plays Henry LaMontagne, and Phoenix plays Michael LaMontagne.
In Criminal Minds: Evolution Season 3, which aired from May 8 to July 10, 2025, on Paramount+, A.J. Cook filmed deeply emotional scenes with Mekhai and Phoenix in their real-life roles as her on-screen children. She described the experience of watching her own sons act, calling it something special because their real family and on-screen family connected in a uniquely meaningful way.
Nathan has shared moments of fatherhood on social media with his characteristic humor. He once posted a photo of Phoenix washing the car and joked it was “child labor” in exchange for candy. He shares pictures of hiking trips, outdoor adventures, and family time that show exactly the kind of father he is: present, playful, and focused on the real world over screens.
The Unique Angle: Why Nathan Andersen’s Story Is Different From Every Other Celebrity Husband
Most articles about Nathan Andersen treat him as background: a supportive husband, a cancer survivor, a guy who runs a clothing brand. What they miss is the specific kind of courage it takes to build your own identity when your wife is one of the most recognizable faces on American television.
Think about what Nathan Andersen has done in the years since A.J. Cook became famous. He stepped away from Hollywood when it no longer suited him. He spent a decade learning business the hard way, inside someone else’s company, before starting his own. He spent four years developing a product that almost no one initially believed in. He survived cancer quietly, without press releases or magazine covers. He raised two sons who are now working actors in their own right.
None of that happened because of A.J. Cook’s fame. All of it happened alongside it. Nathan Andersen is not a man who benefited from his wife’s profile. He is a man who built a parallel life with his own hands while she built hers. That is a rarer story than it might seem, and it is the story that most people searching for Nathan Andersen in May 2026 actually want to understand.
What Is Nathan Andersen Known For?
Nathan Andersen is known as the husband of actress A.J. Cook and the co-founder of Walter Sky, a minimalist outdoor clothing brand. He is also a thyroid cancer survivor who became cancer-free in September 2019. He met A.J. Cook at Utah Valley University in Utah. They married in August 2001. Their sons, Mekhai and Phoenix, have both appeared in Criminal Minds: Evolution on Paramount+.
Nathan Andersen on Social Media
Nathan Andersen keeps a minimal social media presence. He uses Instagram under the handle @nathanandy. His posts tend to be personal and infrequent, mostly covering outdoor adventures, moments with his sons, and the occasional Walter Sky update.
He does not use social media as a personal branding tool. He is not posting daily, chasing followers, or building a parallel celebrity persona. What he shares tends to feel genuine because it is not calculated. Fans who follow him get a glimpse of someone who genuinely prefers climbing mountains to attending press junkets.
Nathan Andersen’s Net Worth
As of 2025 to 2026, Nathan Andersen’s estimated net worth is around $4 million. Much of this comes from his clothing brand Walter Sky and other business ventures. His success did not happen overnight. It came from patience, creativity, and a strong belief in his ideas.
His wife A.J. Cook, has a separate net worth estimated at approximately $5 million, built through her long career on Criminal Minds and its Paramount+ sequel. The family is financially stable, but Nathan’s wealth is his own, earned through his business rather than through association with his wife’s career.
Nathan Andersen at a Glance: Key Career Timeline
| Year | Event |
| 1978 | Born on May 25 in the United States |
| Late 1990s | Meets A.J. Cook in a film class at Utah Valley University |
| 2001 | Marries A.J. Cook on August 3 |
| 2008 | Son Mekhai Allan Andersen is born |
| 2015 | Son Phoenix Sky Andersen is born |
| 2018 | Launches Walter Sky with brother Wesley Andersen |
| 2019 | Reveals thyroid cancer diagnosis and announces he is cancer-free |
| 2025 | Sons Mekhai and Phoenix both appear in Criminal Minds: Evolution Season 3 |
FAQ: Everything People Ask About Nathan Andersen
Who is Nathan Andersen?
Nathan Andersen is an American entrepreneur and fashion designer. He is the co-founder of Walter Sky, a minimalist outdoor clothing brand. He is also the husband of actress A.J. Cook and the father of two sons: Mekhai and Phoenix.
How old is Nathan Andersen?
He was born on May 25, 1978. As of May 2026, he is 47 years old.
Who is Nathan Andersen’s wife?
His wife is A.J. Cook, the Canadian actress best known for playing Jennifer “JJ” Jareau on Criminal Minds and Criminal Minds: Evolution. They married on August 3, 2001.
How did Nathan Andersen meet A.J. Cook?
They met in a film class at Utah Valley University in Salt Lake City, Utah, in the late 1990s. Their friendship grew into a relationship and eventually marriage.
What is Walter Sky?
Walter Sky is a minimalist outdoor clothing brand co-founded by Nathan Andersen and his brother Wesley Andersen. It focuses on high-quality, versatile pieces designed for people who travel, hike, and live actively. Nathan spent four years developing the brand before launching it in 2018.
Did Nathan Andersen have cancer?
Yes. Nathan Andersen was diagnosed with thyroid cancer and kept the battle private during treatment. In September 2019, he posted on Instagram to announce he was cancer-free. A.J. Cook also shared the news publicly with a heartfelt message of support.
How many children does Nathan Andersen have?
He has two sons with A.J. Cook: Mekhai Allan Andersen, born in 2008, and Phoenix Sky Andersen, born in 2015. Both boys have appeared on Criminal Minds: Evolution as their mother’s on-screen children.
Did Nathan Andersen’s sons appear on Criminal Minds?
Yes. Mekhai plays Henry LaMontagne and Phoenix plays Michael LaMontagne on Criminal Minds: Evolution, the on-screen children of A.J. Cook’s character JJ. Both appeared in Season 3, which aired on Paramount+ in 2025.
What is Nathan Andersen’s net worth?
His net worth is estimated at approximately $4 million as of 2025, earned primarily through Walter Sky and his business ventures.
Is Nathan Andersen on social media?
Yes. He uses Instagram under the handle @nathanandy. He posts infrequently and keeps his content personal, covering family life and outdoor activities rather than building a public persona.
What does Nathan Andersen do for a living?
He runs Walter Sky, the clothing brand he co-founded with his brother Wesley Andersen. He is also known to be involved in other business ventures, though he keeps the details private.
Why is Nathan Andersen famous?
He is known primarily as the husband of A.J. Cook, though he has also drawn attention in his own right as the co-founder of Walter Sky and as a cancer survivor who shared his recovery publicly in 2019.
Conclusion
Nathan Andersen is not famous for being famous. He is not riding a wave of recognition that belongs to someone else. He built a brand from scratch over four years, survived cancer without a press tour, raised two sons who are now working actors, and stayed married for over two decades to one of television’s most beloved actresses.
The thing most people miss when they search for Nathan Andersen is that his story is about what you can build when you stop trying to be seen. He chose business over Hollywood, mountains over red carpets, and family over fame. In May 2026, that choice still looks like the right one.
Behind every well-grounded public figure, there is usually someone like Nathan Andersen quietly making sure the whole thing holds together.
For more background on thyroid cancer survivorship and treatment outcomes, see the thyroid cancer Wikipedia page.
