When proponents of cognitive externalism (CE) have turned to empirical studies in cognitive science to put the framework to use, they have typically referred to perception, memory or motor coordination. Not much has been said about reasoning. One promising avenue to explore here is the theory of bounded rationality (BR). In this paper, we try to clarify the potential relationship between these two programs. We start by discussing Andy Clark’s interpretation of BR, which we find unconvincing in several respects. Next, we take a closer look at CE in order defend a version of it that stands against mainstream internalism without committing itself to constitutional claims about the mind. We then turn to analyze BR from the CE perspective. Finally, we argue that internalism about cognition cannot explain important aspects of the BR program.