Strategic behavior emerges when two or more organisms interact. Our brains evolved to track others’ behavior as part of the environment and build mental models of others’ strategies and future actions. In this chapter, we review recent advances in the study of strategic decision-making in the human brain at the level of functional brain networks. We discuss general approaches to computational models of strategic behavior and evidence supporting their neural implementation. We then turn to specific issues, including neural representation of the social context, strategic uncertainty, and mechanisms such as belief-based learning, mentalization, and high-order strategic reasoning. We conclude with potential future directions and methodological developments.