Le Boeuf was born and raised in southern Louisiana. He received his BA from UC Berkeley in 1960. He received an MA at San Francisco State in 1962 studying behavioral pharmacology under Lewis Petrinovich. He returned to UC Berkeley and received his PhD in behavioral endocrinology in 1966 under Frank A. Beach.

After a year at UC Davis, Le Boeuf took a position as Assistant Professor of Biology at UC Santa Cruz in the fall of 1968. In 1971 he was promoted to Associate Professor of Biology and in 1977 to Professor of Biology. He was Visiting Professor of Biology at Harvard University in 1972 and the Large Animal Research Group at Cambridge University in 1985. In 1994, he retired from lecturing and became a Research Professor in Biology. From 1999 to 2000, Le Boeuf assumed the position of Interim Vice Chancellor for Research. He has been the Associate Vice Chancellor since 2001.

In his research on seals, Le Boeuf has been Chief Scientist on numerous National Science Foundation sponsored expeditions on Scripps Institution of Oceanography vessels with destinations in Mexico, Canada and southern Alaska. He has as also led numerous expeditions to California Islands, Argentina, the Galapagos Islands, and Japan.

He received continuous funding from the National Science Foundation from 1972 to 2000 for his research on the biology of elephant seals. His research on marine mammals, birds and fishes has also been funded by grants from the National Geographic Society, the Office of Naval Research, the Packard Foundation, the National Oceanic and Atmospheric Administration, UC Mexus, the Mineral Management Service, the Subantarctic Committee on Antarctic Research, Wildlife Conservation International of the New York Zoological Society, the Monterey Bay National Marine Sanctuary and the Owings Foundation, as well as contracts from the Southwest Fisheries Center and the Bureau of Land Management.

In 1997 to 2000, he consulted on marine mammals with Mitsubishi Corporation, Latham & Watkins, Ropes & Gray, and Skadden, Arps, Slate, Meagher & Flom. He served as Scientific advisor to the Marine Mammal Commission from 1989 to1993. He has reviewed numerous NSF proposals through the years and served on NSF review panels in Population Biology and Physiological Ecology and Polar Biology. He was a member of the board of editors of the journal, Marine Mammal Science and letters editor from 1989 to1995. He has been on the Advisory Board of the Journal of Ethology since 1999. He was a Trustee of the UC Santa Cruz Foundation from 1996 to 2002.