In the face of escalating global challenges, psychologists have a vital yet underutilised role in promoting sustainable development. This chapter explores how psychology education can prepare future professionals to address complex societal and environmental issues. Drawing on psychological theories of behaviour, emotion, learning, and social dynamics, it argues that sustainability challenges are fundamentally behavioural and thus require psychological insight. The chapter presents a course developed at Karolinska Institutet that integrates sustainability into psychology education, aiming to broaden students’ understanding of their professional potential beyond clinical contexts. Through thematic seminars, interteaching methods, and reflective assignments, the course fosters critical thinking, emotional awareness, and collaborative skills. By embedding sustainability into curricula, psychology can contribute meaningfully to systemic change and planetary health.