Brian Duffy (born June 20, 1953, Boston, Massachusetts) is a retired U.S. Air Force colonel and a former NASA astronaut.

In 1975 he received a Bachelor of Science degree in mathematics from the United States Air Force Academy and completed Undergraduate Pilot Training as part of Class 76-10 at Columbus Air Force Base, Mississippi, in August 1976.

[5] Duffy was the pilot on STS-45 Atlantis (March 24 to April 2, 1992), the first of the ATLAS series of missions to address the atmosphere and its interaction with the Sun.

During the 13-day flight, the seven member crew attached the Z1 Truss and Pressurized Mating Adapter 3 to the International Space Station using Discovery's robotic arm and performed four spacewalks to configure these elements.

This expansion of the ISS opened the door for future assembly missions and prepared the station for its first resident crew.