Caring for patients in the outpatient setting is a significant part of many physicians' responsibilities due to healthcare's shift from inpatient to outpatient settings. Outpatient care is complex and characterized by longitudinal relationships among all who work in this setting, including the patients. There is recognition of the need to enhance graduate medical education specifically situated in the outpatient setting. Considering that good educational practices need to be grounded in theoretical principles, the aim of this conceptual article is to analyze and explain learning in the outpatient care setting through a critical appraisal of selected learning theories. Four theories were selected to explore residents' learning in relation to characteristics of the outpatient setting: 1) Cultural-Historical Activity Theory, 2) Situated Learning Theory, 3) Cognitive Development Theory and 4) Self-regulated Learning Theory. These theories were selected for their socio-cultural perspective or their focus on the learner. We highlight the implications for medical education and how these learning theories can inform teaching and learning in the outpatient care setting. For example, identification of contradictions and tensions between educational activity systems can promote expansive and transformational learning. By recognizing the unique opportunities for learning in the outpatient setting and applying learning theories, program directors and education specialists can develop better training programs resulting in more competent physicians to care and serve the needs of patients and society.