Bert Gentry Lee is an American scientist, space engineer, and science fiction author. He is the chief engineer for the Planetary Flight Systems Directorate at the Jet Propulsion Laboratory. Lee has played a crucial role in various missions, including the twin Mars exploration missions that landed in January 2004, the Mars Reconnaissance Orbiter (MRO) in 2006, and the Deep Impact and Stardust missions. He was also the chief engineer of the Galileo project from 1977 to 1988 and served as the director of science analysis and mission planning during the Viking projects.

As an author, Gentry Lee is renowned for co-writing with Arthur C. Clarke on the novels Cradle in 1989, Rama II in 1989, The Garden of Rama in 1991, and Rama Revealed in 1993. He also collaborated with Carl Sagan on the 1980 series Cosmos.