The Berkeley Site Office (BSO) at Lawrence Berkeley National Laboratory (LBNL) is an organization within the U.S. Department of Energy's (DOE) Office of Science with responsibility to oversee and administer the Management and Operating (M&O) contract for LBNL in Berkeley, California.

LBNL, one of ten Office of Science Laboratories, is a multi-program laboratory managed by the University of California. Its primary mission is to deliver breakthrough science and technology in the areas of Renewable energy; Energy Efficiency; Climate Change and Environmental Science; Chemistry and Physics of Matter and Force in the Universe; Computational Science and Advanced Networking; and Biological Sciences for Human Health and Energy Research. Through its oversight role, BSO is affecting the safe and efficient operation of LBNL while enabling the pursuit of visionary research and development in support of DOE's mission.