Frederick Grinnell (born 1945 in Philadelphia, Pennsylvania) is an American cell biologist, also known for his work in bioethics. Currently, he is professor of cell biology at UT Southwestern Medical Center in Dallas, Texas. He took his undergraduate degree in chemistry at Clark University (1966) and Ph.D. in biochemistry at Tufts University (1970). He joined the faculty at UT Southwestern in 1972 and founded the Ethics in Science and Medicine Program and Ethics Grand Rounds in 1998.

Grinnell's early scientific work contributed to the discovery of the biological adhesion protein fibronectin and helped to establish the importance of fibronectin in biomedical engineering and wound repair. Subsequently, his laboratory helped popularize the use of fluid (exudate) from open wounds to analyze the human wound environment and made the discovery that chronic wounds contain degraded fibronectin and high levels of proteolytic enzymes. In recent years, his research has focused on the use of three dimensional collagen matrices containing fibroblasts to learn about the mechanics of fibrous connective tissue.

In bioethics, Grinnell engages in cross-disciplinary work at the boundary between science and philosophy. His goal is to inform public policy and to advance science education and public understanding of science. Grinnell's work in bioethics is centered in the sociology of knowledge, an approach developed through his studies with the phenomenologists Richard Zaner and Maurice Natanson. He has published two books: The Scientific Attitude, now is in its second edition; and Everyday Practice of Science: Where Intuition and Passion Meet Objectivity and Logic, which was a finalist in the 2010 Royal Society Book Prize competition.

For additional information see the Grinnell website.