The team will hold a "Jerseys Off Their Backs" silent auction through May 28 at Minute Maid Park. Fans can bid on game-worn jerseys and make cash donations at the community clubhouse. Players' wives will also sell mystery grab bags with autographed baseballs.
All proceeds will go toward the American Red Cross relief efforts.
"Our hearts and prayers go out to those affected by the tornado," said Astros president of business operations Reid Ryan in a statement. "We have close ties to that community and many friends there. Those are the folks that support us in Oklahoma City, so we're eager to do our part to help them out in a time of need."