Kelley Mack, the actress best known for her role in AMC’s “The Walking Dead,” has died at the age of 33. Her death was confirmed by a representative, who described her as a bright spirit who will be deeply missed by friends, fans, and family alike.
Mack passed away on August 2 with her mother and aunt by her side after a courageous battle with diffuse midline glioma, a rare and aggressive tumor affecting the central nervous system. Her family shared the news through an online statement, writing, “It is with indelible sadness that we are announcing the passing of our dear Kelley.” The statement described her as “a bright, fervent light,” and added that she has already “come to many of her loved ones in the form of various butterflies.”
Earlier this year, Mack publicly revealed her diagnosis on Instagram. She explained that what began as persistent lower back pain eventually led to shooting pains in her legs and back. After a biopsy on her spinal cord, she was diagnosed with diffuse midline glioma, a rare form of astrocytoma cancer. Due to complications from the surgery, she lost the use of her right leg and most of her left, which required her to use a walker and wheelchair.
According to the National Cancer Institute, diffuse midline gliomas originate in the brain or spinal cord and represent a rare subtype of glial tumors. In the U.S., only about 3,940 people are estimated to be living with the disease. Symptoms can include double vision, swallowing difficulties, loss of balance, and weakness in the limbs. Treatment options vary depending on individual cases and may include chemotherapy, radiation, surgery, or targeted medications. The relative five-year survival rate is approximately 42 percent, though prognosis depends heavily on tumor grade and patient age.
Kelley Mack was widely admired not just for her talent, but also for her determination and resilience. Despite her diagnosis and declining health, she remained in close contact with fans and supporters, using social media to raise awareness about rare cancers and share her personal journey.
She rose to fame playing Addy in season 9 of “The Walking Dead,” where she won praise for her gripping performance. Her other notable television appearance was as Penelope Jacobs in season 8 of NBC’s “Chicago Med,” which will return for its 11th season later this year. She also starred in the psychological horror film “Broadcast Signal Intrusion,” where she played the role of Alice.
Beyond acting, Mack was a talented writer, producer, and voiceover artist. Her versatility and dedication to her craft made her a standout figure in the entertainment industry. Friends and collaborators have remembered her as passionate, creative, and deeply kind.
Born Kelley Klebenow in Cincinnati, Ohio, she grew up across multiple states, including North Carolina and Illinois. She was the oldest of three children and graduated from Chapman University in California in 2014. For the past decade, she lived and worked in Los Angeles, where she built a successful career in film and television. Her younger brother, Parker Mack, is also an actor.
In addition to her screen work, Mack was actively involved in writing and producing independent projects and was known for her thoughtful and introspective creative voice. Her loss is being felt deeply within the entertainment community and among those who followed her courageous personal story.
Kelley Mack’s legacy lives on in the characters she brought to life and the strength she showed in the face of adversity. She leaves behind a body of work and a spirit that touched countless lives.