Hollywood Mourns: Kelley Mack, Beloved Star of The Walking Dead and 9-1-1, Passes Away at 33

When the entertainment world bids farewell to a rising star too soon, the sorrow lingers like an unfinished melody.

Such is the case with Kelley Mack—an actress whose warmth, creativity, and resilience lit every screen she graced.

Tragically, on August 2, 2025, she passed away at just 33 years old in her hometown of Cincinnati, Ohio, after a courageous battle with a rare and aggressive form of cancer—diffuse midline glioma, a cancer of the central nervous system.

She was surrounded by loved ones, including her mother and aunt, when she quietly slipped away

Born Kelley Lynne Klebenow on July 10, 1992, in Cincinnati, she discovered her passion for storytelling early.

A childhood spent appearing in commercials—for brands like Dr.

Pepper, Dairy Queen, and Ross Stores—led to a dream: making people feel something through performance After graduating from Hinsdale Central High School in Illinois, she pursued cinematography at Chapman University, further honing her craft in front of and behind the camera

Kelley’s breakthrough came with her role as Addy in the ninth season of The Walking Dead (2018–2019)—a testament to her ability to navigate emotionally layered, high-stakes drama.

She went on to deliver memorable guest performances in 9-1-1 and Chicago Med, solidifying her range and versatility.

Her film repertoire included independent gems like Broadcast Signal Intrusion, Delicate Arch, and Mr.

Manhattan—each role infused with her quiet depth.

At the time of her passing, Kelley had completed a starring role and executive producer credit in a science-fiction film titled Universal, set for posthumous release.

In late 2024, Kelley courageously shared with fans that she had been diagnosed with diffuse midline glioma, a form of brain/spinal tumor that is extraordinarily rare in adults.

She detailed the harrowing effects of the disease: lower back pain, loss of mobility in her legs, and the need for a walker and wheelchair after spinal biopsy surgery.

Yet even in the face of such adversity, Kelley refused to be defined by tragedy.

She shared small but monumental victories—like walking up stairs with help—a testament to her fierce spirit and determination.

Her passing reportedly caught many—including her representative—off guard.

Kelley had been actively auditioning as recently as June, a sign she remained dedicated and hopeful until the end.

It’s a heartbreaking reminder of how swiftly this disease can take hold, even in someone who was clearly fighting with heart and soul.

A wave of tributes flooded in from colleagues and admirers alike.

Fellow Walking Dead cast members and directors called her “a bright light,” praising her talent and spirit On social media, her sister Kathryn shared a deeply moving message:

“It is with indelible sadness that we are announcing the passing of our dear Kelley.

Such a bright, fervent light has transitioned to the beyond… Kelley has already come to many of her loved ones in the form of various butterflies… She will be missed by so many to depths that words cannot express.”
She added in her signature candor and love:
“I’m so f***ing proud of her.”

Those words—both tender and fierce—echo the essence of the Kelley Mack we remember: a powerhouse of creativity, courage, and devotion.

Plans are underway for a celebration of Kelley’s life.

Her memorial will take place on August 16 in Ohio, with a future event planned in Los Angeles to honor her life among friends and colleagues.

More than her roles, it’s Kelley’s warmth, her collaborative spirit, and her courage in the face of unimaginable illness that define her legacy.

Her obituary captures it best: she “cherished time with her family and friends, finding joy in collaboration and storytelling,” and was noted for her unwavering support for others.

Kelley Mack’s passing leaves a void in Hollywood—but also a legacy of light.

She reminded us that even in pain, creativity and love endure—and that bravery can sparkle in the smallest moments.

Whether on the screen, behind it, or in the hearts of those who knew her, Kelley’s spirit lives on.

As we remember her, we carry forward not just her work, but her laughter, her resilience, and the beauty she found in storytelling.

May her final role, in Universal, stand as a lasting tribute to an artist taken far too young—but who shone brightly in every role she ever played.