Kelley Mack, born Kelley Lynne Klebenow, passed away on August 2, 2025, at the age of 33, in her hometown of Cincinnati, Ohio, after a courageous battle with a rare and aggressive form of cancer known as glioma of the central nervous system, specifically diffuse midline glioma reported E! News.
Mack gained recognition for portraying Addy in Season 9 of The Walking Dead (2018–2019), appearing in five episodes as a resident of Hilltop Colony. She also appeared in guest roles on 9‑1‑1 (2019) and Chicago Med (2022). Her film credits include key roles in Broadcast Signal Intrusion, Delicate Arch, Universal, and more than 30 other screen appearances alongside producing credits.
A Chapman University graduate with a B.A. in cinematography, Kelley was known for her passion for storytelling. Her resume included voice‑matching Gwen Stacy in Spider‑Man: Into the Spider‑Verse, and commercial work for brands like Dr Pepper, Chick‑fil‑A, and Rakuten alongside her mother.
Mack was diagnosed in September 2024. She then revealed her condition and the consequent loss of mobility in her legs due to a spinal biopsy via her heartfelt Instagram updates. She shared the challenges openly, including navigating with a walker and wheelchair, but remained determined in her recovery.
Her sister Kathryn posted on Instagram on August 5, announcing her peaceful passing with her mother Kristen and aunt Karen by her side. The message described Kelley as “a bright, fervent light” and shared moving imagery about her spirit continuing through the appearance of butterflies to loved ones.
Family, friends, and fans described Mack’s unique warmth, creativity, and unwavering support. She loved hiking, biking, playing piano, pickleball, and traveling activities that reflected her vibrant and adventurous spirit. A remembrance service is scheduled for August 16 in Ohio, with additional celebrations of her life to take place in Los Angeles at a later date.
Kelley’s passing is profoundly sad, especially at such a young age. Yet her life and career left an emotional imprint. Her resilience, artistry, and kind nature touched colleagues and fans alike. As her family said, she was a bright, fervent light, and though she’s gone, her legacy lives on in the work she made and the people she inspired.
