Sleep Theory is an American rock band from Memphis, Tennessee. They formed in 2019 and consist of vocalist Cullen Moore, guitarist/unclean vocalist Daniel Pruitt, bassist Paolo Vergara, and drummer Ben Pruitt. The band began as a solo project of Moore's, a US Army veteran, who was then joined by Vergara. The band blends styles of heavy metal and R&B. They released their debut EP, Paper Hearts, in 2023, which was preceded by the singles "Another Way" and "Numb". The EP generated over 33 million streams in the next few months. On February 5, 2025, they announced that their debut album, titled Afterglow, would be released on May 16, 2025.