Rosina M. Bierbaum (born September 30, 1952) is currently the Roy F. Westin Chair in Natural Economics and Research Professor at the University of Maryland's School of Public Policy.

She also serves as the U.S. Scientific Expert, Permanent Court of Arbitration of Disputes Relating to Natural Resources and/or the Environment, in the Hague.

She also led the US delegations to the IPCC Plenary in Shanghai in 2001; Montreal in 1999; Costa Rica in 1998; and as alternate head in Mexico City in 1996.

She is a member of the John D. and Catherine T. MacArthur Foundation's Science Advisory Council, the International Advisory Board for the journal Frontiers in Ecology and the Environment, the National Research Council's Board on Atmospheric Sciences and Climate, the Design Committee for The Heinz Center's The State of the Nation's Ecosystems project, and the Executive Committee for the Tyler Prize for Environmental Achievement.

Before joining the School of Natural Resources and Environment (SNRE, University of Michigan), Bierbaum was acting director of the Office of Science and Technology Policy (OSTP).

She co-authored Confronting Climate Change: Avoiding the Unmanageable and Managing the Unavoidable, a report prepared at the request of the Commission on Sustainable Development (2007).

In 1993, she directed and was the primary author of the two-volume study, Preparing for an Uncertain Climate, which outlines a sustainable development strategy for the United States.

Bierbaum's doctoral work focused on understanding how multiple environmental stresses affect physiological parameters of growth, reproduction and glycogen storage in shellfish and their symbiotic organisms (pea crabs).