Heartbreaking Loss: Kelley Mack, ‘Walking Dead’ Actress, Dies at 33

Kelley Mack, a film producer and actress who appeared in “The Walking Dead” and “Chicago Med,” has died. She was 33.

Born Kelley Lynne Klebenow, the Chapman University graduate died Aug. 2 in her hometown of Cincinnati following a battle with glioma of the central nervous system. Her agent, Julie Smith, confirmed the news to USA TODAY on Aug. 5.

According to the National Cancer Institute, gliomas are groups of tumors formed from abnormal glial cells, which “support and protect the brain’s nerve cells” and are found in the brain and spinal cord. They are “the most common type of malignant primary brain tumor in adults,” per the NCI.

Though Mack also did work on commercials and short films, her biggest roles saw her on screen on Season 8 of “Chicago Med” as Penelope Jacobs. She also played Addy in Season 9 of “The Walking Dead.”

Her big-screen credits included Broadcast Signal Intrusion (2021), Delicate Arch (2024) and the soon-to-be-released Universal (2025), on which she also served as executive producer.

She lived and worked in the Los Angeles area for the past 11 years.

The oldest of three kids, Kelley Lynne Klebenow was born in Cincinnati on July 10, 1992, and raised in Wyoming, Ohio; Mount Lookout, Ohio; Ellisville, Missouri; Avon, Connecticut; Charlotte, North Carolina; and Hinsdale, Illinois.

Her love for storytelling blossomed as a youngster when she received a mini video camera as a birthday gift.

She acted in commercials as a child and earned an award from Tisch School of the Arts for her turn as Chloe in The Elephant Garden (2008), which also won the Student Visionary Award at the Tribeca Film Festival.

Kelley Mack, who played the Hilltop Colony resident Addy on the ninth season of AMC’s The Walking Dead in 2018-19, died Saturday in her birthplace of Cincinnati after a battle with glioma of the central nervous system. She was 33.

Mack also appeared on episodes of Fox’s 9-1-1 in 2019 and NBC’s Chicago Med in 2022 and did lots of commercials, showing up in spots for Dr Pepper (in the fictional town of Fansville), Ross Stores, Budweiser, Eli Lilly, Dairy Queen, Chick-fil-A and, with her mom, Rakuten.