As part of his role, Ryan will serve as an advisor to Crane and General Manager Jeff Luhnow. The Hall-of-Famer and all-time MLB strikeout leader also joins his son, Reid Ryan, who is the Astros president of business operations.
"We're extremely pleased to have Nolan as part of our organization," Crane said. "We will use his experience, expertise and knowledge to improve the Astros in all areas. He will be an integral part of our management team. Nolan wants to be a part of our success moving forward."
"I'm very excited to be back with the Astros," Nolan Ryan said. "I'm happy to assist Jim, Jeff and Reid in any way I can. The Astros have a solid foundation with a strong farm system. I think the future is bright for Houston and I'm looking forward to my involvement."
Ryan, 67, entered the big leagues in 1965 with the New York Mets and played 27 seasons, nine of which were with the Astros. Ryan pitched for the Angels before coming to Houston and then with the Rangers after leaving the Astros.
He would later become CEO of the Texas Rangers, a position he held until October of last year when he resigned.
For his career, Ryan has a record of 324-292 with an ERA of 3.19. He recorded 5,714 strikeouts in his career.