Kelley Mack, Known for The Walking Dead, Passes Away at 33 After Brave Glioma Fight

Kelley Mack, best known for her role as Addy on The Walking Dead Season 9, passed away at age 33 on August 2, 2025 in her hometown of Cincinnati after a courageous battle with a rare and aggressive form of brain cancer known as diffuse midline glioma.

Born Kelley Lynne Klebenow on July 10, 1992, Mack discovered her passion for storytelling early in life, inspired by a video camera she received at a young age. She honed her craft through early roles in commercials before pursuing formal study at Chapman University’s Dodge College of Film, graduating with a cinematography degree in 2014.

Over the span of her career, Mack amassed more than 35 acting credits and 5 producer credits, appearing in series such as Chicago Med and 9-1-1, and films including Broadcast Signal Intrusion and Delicate Arch. She also voiced various commercials and promotional roles, including serving as Hailee Steinfeld’s voice match for Gwen Stacy in Spider-Man: Into the Spider-Verse promotions, and appeared in campaigns for brands like Dr. Pepper, Chick‑fil‑A, and Dairy Queen.

Her breakthrough came in 2018 when she joined The Walking Dead as Addy, a resident of Hilltop Colony. Originally intended for a two-episode arc, her role was extended due to her performance and audience response, cementing her presence in the franchise and in genre television.

Mack’s illness was first revealed in late 2024, following persistent back pain that led to a diagnosis of diffuse midline glioma in January 2025. The disease progressed rapidly and resulted in partial paralysis after a spinal biopsy. Mack faced these challenges with openness and determination—documenting milestones such as re-learning to walk with assistance, humor, and resilience.

On the evening of August 2, surrounded by her mother Kristen and aunt Karen, she passed peacefully. Her family later shared an emotional statement noting that butterflies—symbols of transformation and hope—have appeared to many loved ones since her passing. A memorial service will be held in Ohio on August 16 to honor her life and legacy.

Fans and colleagues responded with an outpouring of grief and admiration. Actress Alanna Masterson, who also appeared on The Walking Dead, remembered Kelley as “an incredible human” and shared pride in having worked alongside her. Mack was widely praised for her warmth, creativity, and empathy—attributes that left an indelible mark on everyone she encountered.

She is survived by her parents Kristen and Lindsay Klebenow, sister Kathryn, brother Parker (also an actor), grandparents Lois and Larry Klebenow, and her partner Logan Lanier. Her final completed film, Universal, is due for release posthumously, where she served both in front of the camera and as executive producer.

Kelley Mack’s legacy lies not only in her roles but in her authentic engagement with life and storytelling. Her talents, courage, and compassionate spirit inspired many—and her memory will endure through her work and the love she shared.