The Chief of the Astronaut Office is the most senior leadership position for active astronauts at the National Aeronautics and Space Administration (NASA). The Chief Astronaut serves as head of the NASA Astronaut Corps and is the principal advisor to the NASA Administrator on astronaut training and operations. The Chief's responsibilities include managing Astronaut Office resources and operations and helping to develop operating concepts and assignments for astronaut flight crew.

The NASA Astronaut Corps is a unit of the United States National Aeronautics and Space Administration (NASA) that selects, trains, and provides astronauts as crew members for U.S. and international space missions. It is based at Johnson Space Center in Houston, Texas.