Tech also promoted Otis Mounds, 39, from graduate assistant to assistant coach in charge of cornerbacks.
"It's my goal to bring our defense to a championship level and Chad Glasgow is the right person for the job," Texas Tech coach Tommy Tuberville said in a statement. "With his experience and knowledge of the game and recruiting, he will be a great addition to our staff."
Glasgow replaces James Willis, who was at Tech for one season before leaving the program in late December.
Jeff Caplan covers colleges for ESPNDallas.com.