The overarching goals of the Well-being of the ECE Workforce in Low-Resourced Locations (WELL) study are to investigate individual-, interpersonal-, and systems-level factors that are most strongly associated with worker well-being in Head Start settings; to implement the WELL intervention, a multi-level, multi-strategy intervention, via partnerships with five large Head Start agencies in Colorado; and to assess the intervention’s implementation and effectiveness to improve worker well-being. The project will include a stepped wedge cluster randomized control trial (RCT) to examine the effectiveness of the WELL intervention as well as the implementation factors that support fidelity to the intervention.