The competency of supervision is one that is receiving increased attention in the professional psychology literature. References to supervision in historical and current competency models including the benchmarks are described to illustrate this. Ways in which our understanding of the supervision competency and competency-based education and training broadly is advanced through this major contribution are noted, including focus on empirical support for the essential components of the competency, considerations of how competency models work and do not in other countries, and attention to the interrelationships between competencies. While this major contribution helps expand the scholarly literature on the competency of supervision, challenges remain in the broader adoption of competency-based education and training, including program and systems-level support and the need to identify effective education and training practices to promote competency development.