Kelley Mack of ‘The Walking Dead’ and ‘9-1-1’ dies at age 33 from cancer

Kelley Mack, an actress known for her roles in “The Walking Dead” and “9-1-1,” has died. She was 33. 

Mack, born Kelley Lynne Klebenow, passed away peacefully on August 2 in her hometown of Cincinnati, Ohio, her sister confirmed to Fox News Digital. The actress had been fighting cancer: glioma of the central nervous system.

Her sister, Kathryn Klebenow, also shared the news on Mack’s Instagram page, writing, “It is with indelible sadness that we are announcing the passing of our dear Kelley. Such a bright, fervent light has transitioned to the beyond, where we all eventually must go.”

STARS WE’VE LOST IN 2025

Kelley Mack announced she’d been diagnosed with cancer in January. (Barry Brecheisen/Getty Images)

She detailed that “Kelley passed peacefully on Saturday evening with her loving mother Kristen and steadfast aunt Karen present. Kelley has already come to many of her loved ones in the form of various butterflies. She will be missed by so many to depths that words cannot express.”

Mack first shared her diagnosis in January with an Instagram post in which she wrote in part, “In September, I moved into a new apartment with my boyfriend, Logan. For a month after that, I had persistent lower back pain and thought I slipped a disc. A few weeks later, I had neuropathic itching in my right quad. And then, the shooting pains in my legs and back began, which resulted in me having to sleep in a recliner for a month because laying down was too painful.”

She continued, “On Thanksgiving Eve, I had emergency MRIs done at the hospital, which revealed an abnormal mass in my spinal cord. Fast forward to now – I have been diagnosed with #diffusemidlineglioma, an extremely rare type of #astrocytoma #cancer. Due to the biopsy surgery on my spinal cord, I have lost the use of my right leg and most of my left leg, so I now get around with a walker and a wheelchair.”

She posted several updates on her health, sharing her last on March 26 – a video of herself “re-learning to walk.”

Born on July 10, 1992, Mack was raised in a close-knit family, growing up in Ohio, Missouri, Illinois and North Carolina before attending Chapman University in Orange, California, where she earned a degree in Cinematography.

Actress Kelley Mack on the red carpet for “Broadcast Signal Intrusion” during the 57th Chicago International Film Festival. (Barry Brecheisen/Getty Images)

While continuing to build an impressive career in both acting and production, the actress was most recognized for her role as Addy in Season 9 of “The Walking Dead.” Mack has additional television credits, including her role as Penelope Jacobs in “Chicago Med.” 

LIKE WHAT YOU’RE READING? CLICK HERE FOR MORE ENTERTAINMENT NEWS

She was also featured in several national commercial campaigns, including in a Rakuten commercial with her mother, Kristen. The commercial was filmed this past April. 

In addition to her work on screen, Mack was also a passionate filmmaker. She held five producer credits, including the critically acclaimed horror feature “On The Black,” a 1950s-era college baseball story co-written with her mother. The project, distributed by AMC’s Shudder, earned the Jury Choice Award at the Atlanta Horror Film Festival.

The actress had been quietly fighting cancer, as she battled glioma of the central nervous system, her family confirmed in an online statement.  (Amanda Edwards/Getty Images)

Mack’s creative journey began early. She received a mini video camera as a birthday gift, and sparked what would become a lifelong passion for storytelling. Her breakout performance as Chloe in the 2008 independent film “The Elephant Garden” earned her an Acting Award from Tisch School of the Arts and recognition at the Tribeca Film Festival.

As a voice actor, she was featured in high-profile projects, including the Oscar-winning, “Spider-Man: Into the Spider-Verse.”

CLICK HERE TO SIGN UP FOR THE ENTERTAINMENT NEWSLETTER

Outside of work, Mack was known for her adventurous spirit — she loved hiking, biking, tennis, playing piano and exploring new places. Friends said she brought energy and joy to everything she did.

Outside of work, Mack was known for her adventurous spirit—she loved hiking, biking, tennis, playing piano and exploring new places. (Barry Brecheisen/Getty Images)

“She cherished time with her family and friends, finding joy in collaboration and storytelling,” her family continued to share in a statement. “Her infectious enthusiasm and dedication to her work inspired countless others in the industry and beyond.”

Mack is survived by her parents, Kristen and Lindsay Klebenow, her sister, Kathryn, her brother, actor Parker Mack, her grandparents, Lois and Larry Klebenow, and her boyfriend, Logan Lanier.

A celebration of her life will be held on August 16 at the Glendale Lyceum in Ohio, with a separate memorial planned in Los Angeles.

CLICK HERE TO GET THE FOX NEWS APP