Kelley Mack, aged 33, passes away after courageous battle with rare cancer

Actress and producer Kelley Mack, best known for her role as Addy in Season 9 of The Walking Dead, passed away peacefully on Saturday evening in her hometown of Cincinnati, surrounded by her mother Kristen and aunt Karen, her family announced.

Born on July 10, 1992, Mack was widely celebrated for her vibrant spirit and dedication to storytelling. She earned her Bachelor’s degree in Cinematography from Chapman University before moving to Los Angeles, where she worked for over a decade in film, television, voice-over, and commercial work.

She held 35 acting credits and served as executive producer on five projects, including her final film Universal, completed just weeks before her death .

In September 2024, Mack began experiencing persistent lower back pain, neuropathic itching, and shooting leg pain. An emergency MRI revealed a mass on her spinal cord. She was diagnosed with diffuse midline glioma (DMG), a rare and aggressive grade IV cancer of the central nervous system. A subsequent biopsy led to the loss of mobility in both legs, requiring use of a walker and wheelchair.

In the months that followed, she underwent proton radiation treatment and documented her progress through social media. Notably, in March 2025, she posted a video showing early recovery milestones—learning to walk stairs again—with emotional support from her partner Logan Lanier.

Kelley’s sister shared a heartfelt Instagram tribute on August 5:

“It is with indelible sadness that we are announcing the passing of our dear Kelley… Such a bright, fervent light has transitioned … She will be missed by so many to depths that words cannot express.”
“Kelley has already come to many of her loved ones in the form of various butterflies.”
“She would want you all to know how much she loves you … I’m so f‑‑‑‑‑g proud of her.”

A public memorial service is scheduled for August 16, 2025, in Glendal(e), Ohio, with a future celebration of life planned in Los Angeles.

About Kelley Mack

• Born Kelley Lynne Klebenow, July 10, 1992, in Cincinnati, Ohio

• Best known for her role as Addy on The Walking Dead Season 9

• Also appeared in Chicago Med, 9‑1‑1, and other indie productions such as Broadcast Signal Intrusion and Delicate Arch

• Voice-over and commercial work include campaigns for Dr. Pepper, Chick‑fil‑A, Dairy Queen, and match voice for Gwen Stacy in Spider‑Man: Into the Spider‑Verse

• Passionate about tennis, hiking, biking, piano, pickleball, and filmmaking

Cause of death

• Diagnosed with diffuse midline glioma (astrocytoma), a highly aggressive form of cancer affecting the brain or spinal cord

• Passed away from complications related to the tumor

Kelley’s legacy is one of creative brilliance, empathy, and resilience. Her warmth, storytelling drive, and positivity left a lasting impression on colleagues, fans, and loved ones alike. She will be deeply missed.