Bert Gentry Lee is an American scientist, space engineer, and science fiction author.

He is known for his contributions to planetary flight systems and his role as Chief Engineer at the Jet Propulsion Laboratory (JPL) in Pasadena, California. In this position, Mr. Lee is responsible for the engineering integrity of all robotic planetary missions managed by JPL for NASA. His significant works include oversight of missions such as the Curiosity rover to Mars, the Dawn mission to the asteroids Vesta and Ceres, the Juno mission to Jupiter, and the GRAIL missions to the Moon.

Previously, Gentry Lee guided the engineering aspects of the Phoenix and twin rover missions to Mars, NASA's successful Deep Impact and Stardust missions. He served as Chief Engineer for the Galileo project from 1977–1988 and contributed to the science analysis and mission planning of the Viking projects.

As an author, Gentry Lee is known for co-authoring several novels with Arthur C. Clarke, including Cradle (1989), Rama II (1989), The Garden of Rama (1991), and Rama Revealed (1993). He also worked alongside Carl Sagan on the 1980 series Cosmos.