Kelley Mack, an actress best known for her portrayal of Addy on The Walking Dead, has died at the age of 33 following a courageous battle with a rare form of cancer, according to a statement posted by her family on her official Instagram page. Mack passed away peacefully on Saturday evening, August 3, surrounded by loved ones.
“It is with indelible sadness that we are announcing the passing of our dear Kelley,” her family wrote in the statement. “Such a bright, fervent light has transitioned to the beyond, where we all eventually must go.” The family added that she had “already come to many of her loved ones in the form of various butterflies,” in what many interpret as a symbolic gesture of her enduring spirit.
Mack’s acting career spanned both live-action and voiceover work, but it was her performance as Addy — a brave survivor and a member of the Highwaymen — in The Walking Dead that earned her widespread recognition. She appeared in multiple episodes of the long-running AMC series and quickly became a fan favorite for her emotional depth and resilience on-screen.
She also took on roles in several indie films and TV projects and built a parallel career as a voice artist, earning praise for her dynamic vocal range and commitment to every role she undertook.
In a heartbreaking post shared in January, Mack disclosed that she had been diagnosed with diffuse midline glioma, an aggressive and rare type of astrocytoma cancer located in her spinal cord. The diagnosis followed a series of troubling symptoms that began in the fall of 2023, including back pain, neuropathic itching, and severe leg pain that eventually left her reliant on a walker and wheelchair.
“On Thanksgiving Eve, I had emergency MRIs done at the hospital, which revealed an abnormal mass in my spinal cord,” she wrote in the post. “Due to the biopsy surgery, I have lost the use of my right leg and most of my left leg.” Despite her declining health, she remained active on social media, documenting her treatment journey and connecting with fans who offered messages of love and encouragement.