Mia Bird is a policy analyst and applied researcher focused on criminal justice reform and the intersections of criminal justice, health, and social safety net policies. Bird is an assistant adjunct professor at the Goldman School of Public Policy and expert affiliate with the California Policy Lab at the University of California, Berkeley.

Before joining the Berkeley faculty, she spent seven years at the Public Policy Institute of California as a research fellow. At PPIC she co-founded and directed the Multi-County Study, an effort to create the first individual-level, linked criminal justice data infrastructure for the state and counties in California. These data allowed for research to monitor and evaluate of the effects of a wave of criminal justice reforms. Bird moved to Berkeley in 2019 to continue the effort to build a sustainable criminal justice data system and to leverage these data to inform policy decisions and evaluate policy reforms.

Her work has been funded by Arnold Ventures, the Blue Shield Healthcare Foundation, the California Endowment, the California Wellness Foundation, the National Institute of Justice, and the Russell Sage Foundation. Bird has been published in the ANNALS of the American Academy of Political and Social Science, Criminology and Public Policy, and the Criminal Justice Policy Review. She consults widely with research centers and organizations working on criminal justice issues in California, including the California Commission on the Reform of the Penal Code, California Committee on Criminal Justice and Behavioral Health, California State Association of Counties, and Chief Probation Officers of California. Bird holds a PhD in public policy, an MA in demography, and an MPP from the University of California, Berkeley.