The Walking Dead fans have taken to social media to remember late actress Kelley Mack, who died of glioma of the central nervous system (a rare type of astrocytoma cancer) on Aug. 2. She was 33 years old.
In January 2025, Mack announced her diagnosis as family, friends, and fans rallied around the young woman, following her journey.
Mack's CaringBridge page contains all the information regarding her celebration of life in Ohio on Aug. 16. The site also chronicles her journey, and her family has posted a formal two-page tribute honoring her life.
Per the tribute, Mack grew up with a close-knit family and is described to have a "vibrant spirit, creative passion, and dedication to storytelling."
Mack was born Kelley Klebenow in Ohio and lived in several other states before attending Dodge College of Film at Chapman University in Orange, California. For the past 11 years, she lived and worked in Los Angeles, where a celebration of life will be held at a later date.
During her career, Mack amassed 35 acting and five producing credits. This includes her roles in numerous TV and movies, including Chicago Med, Broadcast Signal Intrusion, 9-1-1, Coventry, and more. She has been featured in an extensive list of commercials.
During season 9 of The Walking Dead, Mack was introduced as Adeline, or Addy, a member of the Hilltop community. She was first seen in episode 907, "Stradivarius," being trained by her good friend Gage (Jackson Pace) with hopes of becoming a Hilltop guard. She was also good friends with Rodney (Joe Ando Hirsh). She was much more mature and sensible than her friends and didn't always agree with her friends' idea of fun.
On X, fans have shared tributes to Mack, some even meeting her at events such as Walker Stalker Con, the fan-run Walking Dead convention. Scott M. Gimple also shared a comment on social media.
heard about the passing of kelley mack. i made her a friendship bracelet back in 2019 at wsc atlanta, she was a very sweet girl. gone far too young :( pic.twitter.com/FUeJSQ1kqH
— nicole 🕷 (@endlingz) August 6, 2025
It’s with immense sadness that we share the passing of Kelley Mack at the age of 33.
— The Walking Dead World (@TWalkingDWorld) August 5, 2025
Kelley is known to fans of #TheWalkingDead for portraying the character of Addy in Season 9.
Our sincere thoughts are with her loved ones during this difficult time. pic.twitter.com/u810HeyGtX
Sad news about a massively talented member of the TWD family. We’re grateful we got to work with Kelley Mack and share her magic with the world. https://t.co/qBb3UpghrY
— Scott M. Gimple (@ScottMGimple) August 6, 2025
Mack showcased her talent with voiceover work, selected as the voice match for Hailee Steinfeld/Gwen Stacy in the Oscar-winning Spider-Man: Into the Spider-Verse. She was also the voice of Gwen in the 2025 Hyundai IONIQ commercial.
In June, Mack announced the premiere of the indie film Universal at the 28th Dances with Films held at the Chinese Theatres in Hollywood. She starred and served as an executive producer for the movie, which also stars Joe Thomas (The Inbetweeners, Fresh Meat, The Festival) and Rosa Robson (Extraordinary, Buffering).
Stephen Portland directed and wrote the sci-fi comedy described as: "A small, down-to-earth film about huge, out-of-this-world concepts." The movie features three characters, set in one location during one weekend.
Universal will be screened at the Portland Festival of Cinema, Animation and Technology on August 10 and the Chain NYC Film Festival on August 11.
Check out the trailer for Universal below.
Our deepest sympathies go out to the family and friends of Kelley Mack. RIP.