Actress and producer Kelley Mack, best remembered for her portrayal of Addy in Season 9 of The Walking Dead, has passed away at the age of 33.
Her family confirmed that Mack died on Saturday in her hometown of Cincinnati after a battle with glioma, a type of cancer affecting the central nervous system.
“It is with immeasurable sadness that we announce the passing of our beloved Kelley,” read a heartfelt post shared Tuesday on Mack’s official Instagram account. “A radiant and passionate soul has crossed over to the next realm, a place we all must someday reach.”
The message, written by Mack’s younger sister, added that she passed peacefully with her devoted mother Kristen and her caring aunt Karen at her side. “Kelley has already appeared to many of us as butterflies 🦋❤️,” her sister noted. “She will be missed beyond what words can express.”
In closing, her sister shared how deeply Kelley loved her fans and friends: “Kelley would want all of you to know how much she loved you. And as her sister, I want you to know how incredibly strong and brave she was—especially in her final decision to return to God. I’m endlessly proud of her.”
Born as Kelley Klebenow on July 10, 1992, she discovered her passion for storytelling early in life after receiving a mini video camera for her birthday. She graduated from Hinsdale Central High School in 2010 and earned a bachelor’s degree in Cinematography from Chapman University’s Dodge College of Film in 2014. She lived and worked in Los Angeles throughout her career.
Over the years, Mack amassed 35 acting credits and five producer credits. She made her screen debut in the short film Violet (2019), before landing her breakout role as Addy in AMC’s The Walking Dead. She also appeared as Penelope Jacobs in Chicago Med (Season 
and made appearances on Fox’s 9-1-1.
Her film credits include starring as Alice in Broadcast Signal Intrusion (2021), Wilda in Delicate Arch (2024), and Ricky in the upcoming feature Universal, for which she also served as executive producer. Other roles include Tina in Mr. Manhattan, along with several short films she both acted in and produced.
Kelley was also recognized for her voiceover work, including her standout role as a voice match for Hailee Steinfeld’s Gwen Stacy in Spider-Man: Into the Spider-Verse, a performance she reprised in a 2024 Hyundai Ioniq commercial. She lent her voice to campaigns for Budweiser, Salvation Army, Herbal Essences, Credit Karma, and more.
Commercially, she featured in well-known ads for Dr. Pepper’s Fansville series, Dairy Queen, Chick-fil-A, and Ross.
Kelley Mack is survived by her parents, Kristen and Lindsay; her sister Kathryn; her brother Parker (also an actor); grandparents Lois and Larry; and her boyfriend, Logan.
