Kelley Mack, the actress best known for her role as Addy in Season 9 of “The Walking Dead”, has sadly passed away at the age of 33. Her family confirmed her death via social media, noting that she died peacefully on August 2, 2025, in her hometown of Cincinnati, Ohio, following a battle with glioma of the central nervous system, a rare and aggressive form of cancer.
“Kelley passed peacefully on Saturday evening with her loving mother Kristen and steadfast aunt Karen present,” read the heartfelt message shared on her Instagram. “She has already come to many of her loved ones in the form of butterflies. She will be missed by so many to depths that words cannot express.”
A Rising Talent Gone Too Soon
Born Kelley Lynne Klebenow on July 10, 1992, Mack grew up across several states including Ohio, Illinois, Connecticut, and North Carolina, before moving to Los Angeles. A graduate of Chapman University’s Dodge College of Film, she held a degree in Cinematography and had spent over a decade building a vibrant career in entertainment.
Mack appeared in hit shows like “The Walking Dead,” “9-1-1,” “Chicago Med,” and voiced characters in major projects including “Spider-Man: Into the Spider-Verse.” She was also known for her national TV commercial work — most notably as Becky in Dr. Pepper’s “Fansville” ads — and voiceovers for Budweiser, Hyundai, and Credit Karma.
What Is Glioma of the Central Nervous System?
Kelley Mack was diagnosed in late November 2024 with diffuse midline glioma, a rare type of astrocytoma cancer that targets the brain and spinal cord. Symptoms began as persistent lower back pain and neuropathic issues before progressing rapidly.
She shared her journey bravely on social media, documenting her pain, treatments, and therapy. After a biopsy on her spine, she lost the use of her legs and required a walker or wheelchair. She began proton radiation therapy in January and had regained some movement by March — even sharing a video of herself re-learning how to walk.
“It felt like I was filming an episode of my new TV show, set on a spaceship floating somewhere in our infinite galaxy,” she wrote about her radiation sessions.
Despite fighting with strength and positivity, by July 2025, Kelley entered respite care — described by her family as the “toughest part of her journey.”
Embed from Getty ImagesRemembering Kelley Mack
Kelley’s passing leaves behind a heartbroken but proud family: her parents Kristen and Lindsay Klebenow, sister Kathryn, brother Parker, grandparents Lois and Larry, and longtime boyfriend Logan Lanier.
The family will host a celebration of life on August 16 in Glendale, Ohio, with a second memorial planned later in Los Angeles.
“Kelley’s legacy will live on through her contributions to film and television, and in the hearts of those who loved her,” her family said. “She will be deeply missed but forever remembered for her talent, kindness, and vibrant spirit.”
Quick Facts – Kelley Mack
- Age at death: 33
- Date of death: August 2, 2025
- Cause: Glioma of the Central Nervous System
- Notable role: Addy in The Walking Dead
- Other credits: 9-1-1, Chicago Med, Fansville ads, Spider-Man: Into the Spider-Verse
- Education: BA in Cinematography from Chapman University
- Voiceover clients: Hyundai, Budweiser, Credit Karma
