A revolution in the measurement and reporting of government performance through the use of published metrics, rankings and reports has swept the globe at all levels of government. Performance metrics now inform important decisions by politicians, public managers and citizens. However, this performance movement has neglected a second revolution in behavioral science that has revealed cognitive limitations and biases in people's identification, perception, understanding and use of information. This Element introduces a new approach - behavioral public performance - that connects these two revolutions. Drawing especially on evidence from experiments, this approach examines the influence of characteristics of numbers, subtle framing of information, choice of benchmarks or comparisons, human motivation and information sources. These factors combine with the characteristics of information users and the political context to shape perceptions, judgment and decisions. Behavioral public performance suggests lessons to improve design and use of performance metrics in public management and democratic accountability.