Chad Gilbert, the founding guitarist and backing vocalist of the pop-punk band New Found Glory, has died at the age of 45. The band and his wife, Lisa Cimorelli, confirmed the news on social media, stating that Gilbert passed away peacefully in his sleep on the morning of September 20. He was surrounded by friends, family, and his wife and mother at the time of his death, as he had wished. Gilbert was diagnosed with a rare adrenal gland cancer in 2021, which later progressed to stage 4 adrenocortical carcinoma — a rare and aggressive form of cancer that affects the outer layer of the adrenal glands and can spread to other parts of the body. In March 2025, he underwent emergency brain surgery after three tumors were discovered. A month later, his diagnosis was updated to stage 4 adrenocortical carcinoma. He had previously endured intense chemotherapy and resumed radiation treatments after a cancerous spot was found in his back in August 2025. His bandmates and wife expressed deep sorrow over his passing, describing the loss as "devastating." Lisa Cimorelli, who married Gilbert in 2020, noted the overwhelming support he received, with many people gathering at the hospital to pay their respects. She highlighted that his greatest accomplishment was being a husband and father. Gilbert is survived by his wife, daughter Lily, mother Jackie, and brother Brian. His bandmates praised his contributions to New Found Glory, noting his guitar playing, songwriting, humor, and drive, which helped shape the band for nearly three decades. Beyond his work with New Found Glory, Gilbert was also a lead vocalist for the band's side project, International Superheroes of Hardcore, and had two stints as the lead vocalist for Shai Hulud. He also worked as a producer and released solo material. Gilbert was previously married to Hayley Williams, lead singer of Paramore, from 2016 to 2017. They had met in 2008 when Williams was still dating his first wife, Sherri DuPree. After their divorce, Williams expressed regret over the marriage and spoke about its impact on her mental health, though both emphasized that they would remain close friends.