Kelley Mack was a dedicated and hard-working actress, producer and voiceover artist best known for playing Addy in The Walking Dead. But Mack’s life was cut short in 2025 after a months-long cancer battle. She was only 33 when she died, and her sister penned a heartfelt Instagram caption announcing her death.
“Kelley passed peacefully on Saturday evening with her loving mother Kristen and steadfast aunt Karen present,” the post read. “Kelley’s Caringbridge link in her bio includes the 2-page formal announcement with information on her upcoming life celebration in Ohio on August 16th. She would want you all to know how much she loves you. And as her sister, I want you all to know how brave that tough SOB was, especially when she decided to make the leap to be reunited with God. I’m so f**king proud of her.”
Below, Hollywood Life has compiled five facts about Kelley.
Kelley Mack Played Addy in The Walking Dead
The Walking Dead fans were first introduced to Mack in season 9. Her character, Addy, was a Hilltop Colony survivor.
Kelley Mack Studied Cinematography
According to her IMDb profile, Mack branched out to more than just acting by working behind the camera a few times. The Ohio native studied film production and cinematography.
Kelley Mack Was a Producer & Voiceover Artist
Per Mack’s IMDb page, she produced a film that got picked up by AMC’s Shudder, and it won the Jury Choice Award at the Atlanta Horror Film Festival.
Kelley Mack Had a Supportive Boyfriend
Mack was dating her boyfriend, Logan, toward the end of her life. In January 2025, Mack shared that she and Logan had just moved into a new apartment together. There, she started experiencing physical pains, which would lead to her cancer diagnosis.
Mack pointed out that her boyfriend was by her side throughout “every second” of her cancer battle.
Kelley Mack Battled a Rare Form of Cancer
It turned out that Mack’s “persistent lower back pain” and “shooting” leg pains contributed to a rare form of cancer called diffuse midline glioma, a type of astrocytoma, she revealed in her January 2025 Instagram post. Astrocytoma is a brain tumor. Diffuse midline glioma is a tumor that begins in the brain or spinal cord, per the National Cancer Institute.
“Due to the biopsy surgery on my spinal cord, I have lost the use of my right leg and most of my left leg, so I now get around with a walker and a wheelchair,” Mack revealed in her announcement.
In the months to come, Mack updated her followers on her progress, which was seemingly going well. The actress had learned to walk without a cane or wheelchair by March 2025, but she died that August.