Advances over the past decade have given biological engineers new insights into the role of genetic circuits in nature and the design of biomolecular circuits to implement biological operations in vitro and in vivo. In this talk I will discuss the use of concepts from systems and control engineering as applied to the analysis and design of biological feedback circuits. After a brief survey of relevant concepts from systems and control theory, I will present some recent results that combine modeling, analysis, design and experimental implementation of biological feedback circuits. These results include the role of redundant bioogical pathways for implementing robust decision-making strategies in cells, the use of biomolecular “breadboards” for prototyping and debugging engineered biomolecular circuits, and the implementation of circuits for regulation of gene expression and biomolecular event detection. Using these results as examples, I will discuss some of the open problems and research challenges in the area feedback control using biological circuits.