Robert Louis Behnken is an American engineer, a former NASA astronaut, and former Chief of the Astronaut Office.

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.