J. Brookes Knight (1888-1960) was born in St. Louis, Missouri. He received his bachelor's degree at Princeton University, 1911, his master's degree at the University of Kansas, 1928, and his Ph.D. at Yale University, 1931. After graduating from Princeton, Knight returned to St. Louis to help in his family's business. During this time he studied fossils from the St. Louis area which were later used as the basis for his thesis at Kansas.
Following his graduation from Yale, Knight remained there for two years as a Research Associate and Sterling Senior Fellow at the Peabody Museum of Natural History. In 1933 he left the Peabody Museum and went to Occidental College in California where he was an Assistant Professor of Geology. From 1934 to 1935, he was in Europe on a Penrose Grant from The Geological Society of America to study Paleozoic gastropod collections in European museums. In 1936, he was appointed Lecturer and Curator of Paleozoic Invertebrate Paleontology at Princeton. During World War II, he also served as Instructor of Geology at Princeton's Army Special Training Program. During the summers of 1931, 1936, and 1938, Knight was an Assistant Geologist with the United States Geological Survey, assisting Philip B. King in studying the Permian fossils of Texas.
In 1945 Knight joined the staff of the United States National Museum (USNM) as a Research Associate in Paleontology, a position which he held until his retirement in 1956 when he was made an Honorary Research Associate. At the USNM Knight was in charge of the Paleozoic gastropods. As a result of his work with these fossils, Knight helped to prepare a section on Paleozoic gastropods for the Index Fossils of North America (1944) and the Treatise on Invertebrate Paleontology published by the Paleontological Society in 1960. He also helped prepare a study of Permian fossils, parts of which were published posthumously.