Kelley Mack: A Star’s Light Dimmed Too Soon by Glioma

Kelley Mack, known to fans as Addy from The Walking Dead, was more than an actress—she was a storyteller, a dreamer, and a fighter. Her vibrant career, marked by roles in Chicago Med, 9-1-1, and The Walking Dead, showcased her talent and heart. Tragically, on August 2, 2025, Kelley passed away at 33 in Cincinnati, Ohio, after a courageous battle with diffuse midline glioma, a rare brain cancer. This is her story—a celebration of her life, her work, and the legacy she leaves behind.

A Cincinnati Dreamer with a Camera

Born Kelley Lynne Klebenow on July 10, 1992, in Cincinnati, Ohio, Kelley’s passion for storytelling began early. As a child, a birthday gift of a mini video camera sparked her love for filmmaking. She’d spend hours creating stories, a habit that followed her to Chapman University’s Dodge College of Film and Media Arts, where she earned a bachelor’s degree in cinematography in 2014. Growing up with her parents, Kristen and Lindsay, and siblings, Kathryn and Parker (also an actor), Kelley’s family nurtured her creativity.

Her first taste of the spotlight came at 16 with a role in the 2008 short film The Elephant Garden. The film won a Student Visionary Award at the Tribeca Film Festival, and Kelley earned an Acting Award from NYU’s Tisch School of the Arts. It was clear: she was destined for greatness.

Captivating Audiences as Addy in The Walking Dead

Kelley’s breakout role came in 2018 as Addy, a resilient member of the Hilltop Colony in Season 9 of The Walking Dead. Appearing in five episodes, she brought depth to Addy, a character navigating love and loss in a zombie-filled world. Her performance, especially in the season finale where Addy faced the Whisperers, resonated with fans. Director Michael E. Satrazemis called her “a bright light,” a sentiment echoed by co-stars like Alanna Masterson, who praised her warmth and talent.

Kelley’s role in The Walking Dead wasn’t just a career milestone; it was a moment that connected her with a global fanbase. Addy’s quiet strength mirrored Kelley’s own, making her a fan favorite among TWD viewers searching for “Kelley Mack Walking Dead” or “Addy TWD.”

A Versatile Talent Across Television and Film

Kelley’s career was a tapestry of diverse roles. In 2022, she played Penelope Jacobs in Chicago Med Season 8, bringing emotional nuance to the medical drama. She also appeared in a 2019 episode of 9-1-1, showcasing her ability to shift genres effortlessly. Her resume included miniseries like Grayson: Earth One (2015), Not Your Average Joe (2016), and Unscrewed (2016), as well as a role in the Modern Family spinoff Schooled.

On the big screen, Kelley shined as Alice in Broadcast Signal Intrusion (2021) and Wilda in the 2024 horror-comedy Delicate Arch. Her final project, Universal (2025), saw her act and serve as an executive producer, a testament to her multifaceted talent. As a voice-over artist, she lent her voice to Gwen Stacy in Spider-Man: Into the Spider-Verse (2018) and a 2024 Hyundai Ioniq commercial. Her commercial work for brands like Dr Pepper, Budweiser, and Chick-fil-A further highlighted her versatility.

Facing Diffuse Midline Glioma with Courage

In September 2024, Kelley shared a devastating diagnosis: diffuse midline glioma, a rare and aggressive central nervous system tumor. Gliomas, which arise from glial cells supporting the brain and spinal cord, account for about 25% of primary brain tumors in the U.S., per the National Library of Medicine. Diffuse midline gliomas, often located in the brainstem or spinal cord, are particularly deadly, with a median survival of 9 to 12 months. They disrupt critical functions like movement and breathing, making treatment challenging.

Kelley faced her illness head-on. A January 2025 spinal cord biopsy left her with limited leg function, requiring a walker and wheelchair. Yet, she shared her journey with grace, posting on Instagram about milestones like climbing stairs with her boyfriend, Logan, by her side. “It’s a big deal for me,” she wrote in March 2025, inspiring countless followers. She underwent proton radiation, but the tumor’s location made surgery nearly impossible. Despite her optimism, calling her illness “a short chapter in my long book,” Kelley passed away peacefully, surrounded by family.

A Legacy of Joy and Resilience

Kelley’s passing sparked an outpouring of love. Her sister, Kathryn, announced her death on Instagram, writing, “Such a bright, fervent light has transitioned to the beyond.” Fans and colleagues, including TWD’s Anthony Michael Lopez, who called her “a sweet and happy soul,” mourned her loss. Kelley’s spirit, symbolized by butterflies in her family’s tributes, continues to inspire.

Beyond acting, Kelley was a hiker, pickleball player, pianist, and traveler who cherished collaboration. Her work as a producer, including a Jury Choice Award-winning project for AMC’s Shudder, showed her creative range. A remembrance in Glendale, Ohio, and a planned Los Angeles celebration of life honor her impact.

Raising Awareness for Glioma

Kelley’s battle highlights the urgent need for glioma research. These tumors, especially high-grade ones like diffuse midline glioma, are difficult to treat due to their location and the brain’s complexity. Symptoms—headaches, seizures, neurological deficits—often appear late, complicating early diagnosis. While surgery, radiation, and chemotherapy are standard, outcomes remain poor for aggressive gliomas. Increased funding and awareness could drive breakthroughs, honoring those like Kelley who fought bravely.

A Light That Lives On

Kelley Mack’s story is one of talent, courage, and love. From her early days filming with a childhood camera to her unforgettable roles, she lived to create and connect. Her battle with glioma, though tragic, showed her strength and inspired countless others. As fans search for “Kelley Mack The Walking Dead” or “Addy Walking Dead,” they’ll find a legacy that transcends the screen—a reminder to live boldly, love deeply, and tell stories that matter.

GTA San Andreas