The Department of Biology (BIO) at the University of Bergen embodies research and research based education within a broad spectrum of biological disciplines. BIO is among the largest departments at the University of Bergen and hosts about 150 research positions. BIO is responsible for three Bachelor programs (Biology, Aquaculture Biology, and Environment and Resources Studies), and fifteen Master programs, including an integrated master and career program in Fish Health, and teacher education with master in Natural Sciences. Integrated in these programs are nearly 600 students.

The research in BIO is organised into 16 different research groups. BIO has a large project profile, and nearly half of the scientific positions are granted through externally financed projects.

The Department of Biology originated in 2004 through a merger of the former Botanical Department, Department of Fisheries and Marine Biology, Department of Microbiology and Zoological Department. In 2006, also the former Centre for Studies of Environment and Resources has been integrated into BIO.