The urgent environmental challenges we now face, from climate change to biodiversity loss, involve people and the planet, the social, and the environmental. Teaching students to become effective socio-environmental problem-solvers requires clarity about concepts and competencies needed to understand and tackle these challenges. Here, we propose an educational framework that describes what students should learn and how they should apply this knowledge to address socio-environmental problems. This framework emphasizes the process of problem-solving and is based on socio-environmental (S-E) synthesis, an integrative, transdisciplinary approach to understanding and tackling complex socio-environmental problems. In addition to identifying the knowledge, skills, dispositions, and practices necessary for S-E problem-solving at the undergraduate and graduate levels, we clarify how one draws on such competencies to inquire about problems and generate solutions for them. Our primary goal is to provide a useful tool to help guide development of curricula, teaching materials, and pedagogies for S-E synthesis and interdisciplinary environmental education more broadly.