CINCINNATI, Ohio — The film and television industry is remembering Kelley Mack, who won fans as Addy in Season 9 of AMC’s The Walking Dead. Mack, whose birth name was Kelley Lynne Klebenow, died at 33 on August 2, 2025, in Cincinnati.
She spent the last months of her life facing diffuse midline glioma, a rare and severe brain cancer. Messages from her loved ones and followers celebrate her lively spirit and creative achievements.
Kelley Mack’s experience with cancer started in September 2024, after ongoing back pain led her to believe she had a slipped disc. The pain grew worse, spreading through her legs and back, often forcing her to sleep upright for comfort.
An MRI in November 2024 uncovered an unusual growth in her spinal cord, and doctors diagnosed her with diffuse midline glioma, a type of astrocytoma that targets the central nervous system. The Mayo Clinic notes this cancer is most often seen in children, but adults can develop it too. Treatment options usually include surgery, radiation, and chemotherapy.
Mack underwent a spinal cord biopsy, which left her unable to use her right leg and with only partial movement in her left. She needed a walker and a wheelchair to get around. In January 2025, she opened up on Instagram about the emotional and physical toll, writing about the strain it placed on her body and mind.
Mack’s faith, family, and boyfriend, Logan Lanier, gave her strength. She received radiation in Cincinnati, and in March 2025, celebrated progress by sharing a video of herself climbing stairs with some help, captioned, “It’s a big deal for me.”
By July 2025, Mack entered respite care, which her family called the hardest phase. She passed away peacefully at home, with her mother, Kristen Klebenow and her aunt Karen by her side. Her sister Kathryn described her as tough and said Mack has now “reunited with God.”
Her Creative Path and Lasting Work
Born 10 July 1992 in Cincinnati, Kelley Mack discovered her love of film early, after getting a video camera for her birthday. She starred in commercials as a child and stood out as Chloe in the 2008 indie film The Elephant Garden, a role that brought her awards from NYU’s Tisch School and Tribeca Film Festival.
Mack graduated from Hinsdale Central High School in Illinois in 2010 and completed her degree in cinematography at Chapman University’s Dodge College in 2014. She later moved to Los Angeles, taking on 35 acting roles and producing five projects.
Her most recognized role was Addy, a member of Hilltop Colony on The Walking Dead. She also appeared in Season 8 of Chicago Med, the series 9-1-1, and films including Broadcast Signal Intrusion (2021) with Harry Shum Jr., Mr. Manhattan (2024), and Delicate Arch (2024).
She was set to star in Universal, scheduled for release in 2025, where she also worked as executive producer.
Kelley Mack voiced Gwen Stacy in promotions for Spider-Man: Into the Spider-Verse and appeared in a Hyundai Ioniq advert in 2024. She built a solid commercial portfolio featuring Dr Pepper, Budweiser, Ross Stores, Dairy Queen, Chick-fil-A, and Rakuten, where she acted opposite her mother in 2025.
As a producer, she received awards for A Knock at the Door, Violet (Top Shorts Film Festival), and Unreal City (Hollywood Fringe Festival).
Mack’s passion also led her to write scripts with her mother, including On The Black, a story inspired by her grandparents’ days at Ohio University. Her family shared that she brought warmth and inspiration to everyone around her.
Community Tributes and Shared Memories
The news of Mack’s death led to an outpouring of tributes from family, friends, colleagues, and fans. On Instagram, her family posted a touching message describing her as “a bright, fervent light.”
They shared that many loved ones saw butterflies as signs of her spirit. Her sister Kathryn praised her bravery and kindness, saying she would want everyone to know how much she loved them.
Her aunt Karen expressed sorrow but spoke fondly of Mack’s joyful spirit, saying she would be the “best angel ever.” Mack’s loved ones talked of her enthusiasm for hiking, pickleball, cycling, piano, travel, and her playful interests, including dark chocolate and sporting a British accent.
She is survived by her parents, Kristen and Lindsay Klebenow, her sister Kathryn, her brother Parker (also an actor), her grandparents Lois and Larry Klebenow, and her boyfriend Logan Lanier.
Former colleagues from The Walking Dead shared their grief. Alanna Masterson, known for her role as Tara Chambler, said she was proud to have worked with Mack. Director Michael E. Satrazemis remembered her as a bright presence on set. Gustavo Gomez, another co-star, said her energy would be remembered.
Anthony Michael Lopez called her someone who “fought so hard.” Fans on social media honoured her talent and kindness, expressing how much she would be missed.
Posts across X (formerly Twitter) reflected the sadness many felt, while some users spread speculation about the cause of her illness. These claims have no verifiable support.
Honouring Kelley Mack’s Life
Kelley Mack’s family will hold a memorial on August 16, 2025, at the Glendale Lyceum in Glendale, Ohio, with a future event in Los Angeles. Her CaringBridge page has a detailed announcement celebrating her creative spirit and kindness.
Mack’s work as an actress, producer, and writer leaves a strong impression on the entertainment industry. Her bravery while facing diffuse midline glioma, along with her positive energy and commitment to storytelling, continues to inspire. Her family said her legacy will carry on through her work and in the hearts of those she loved.
Her memorial will remember Kelley Mack as a talented artist, a caring daughter, and a much-loved friend, whose spirit continues to shine, much like the butterflies that remind her family she is near.
