The university announced his sudden passing on Tuesday.
Temple said Courtney joined the men's basketball staff in June 2025, bringing more than 30 years of collegiate coaching experience to the Owls.
Prior to Temple, the university said Courtney spent five seasons with Miami, where he helped guide the Hurricanes to three NCAA Tournament appearances - including a 2023 Final Four run - and served as interim head coach for the final 19 games of the 2024-25 season following the retirement of Jim Larrañaga.
"I am shocked and heartbroken by the tragic news and passing of my close friend Bill Courtney," Temple head coach Adam Fisher said in a statement. "Bill made such a big impact on our program in such a short time. He was one of the most respected coaches in the country - thoughtful, prepared, and deeply committed to the game and to winning the right way. Bill made every program he touched better, and his loss is felt profoundly by everyone who knew him."
Temple said Courtney was "widely respected for his knowledge of the game and his success across multiple programs."
Information regarding memorial arrangements will be shared when available, Temple said.