Background <p>About one-third of U.S. youth are overweight and most have at least one risk factor that increases their chance of developing cardiovascular or other chronic diseases. School- and research-based physical activity and healthy eating programs can reduce obesity and improve health outcomes; however, schools face many implementation challenges. Healthy School Recognized Campus (HSRC) bundles school- and researched-based programs to improve their implementation and student health outcomes. This paper describes the protocol for a hybrid type 2 implementation-effectiveness, cluster dual randomized controlled trial that evaluates the (aim 1) effectiveness of the HSRC initiative for improving health behaviors and (aim 2) the impact of an implementation strategy – school-to-school mentoring – on HSRC’s delivery.</p> Methods <p>Students in 4th through 9th grade (<i>n</i> = 500) at public schools (<i>n</i> = 20) across East and Central Texas will be randomized at the school level to determine the effectiveness of HSRC (vs. waitlist control condition) on BMI z-score (primary outcome), physical activity measured via accelerometer, and skin carotenoids (i.e., fruit and vegetable intake; secondary outcomes). Assessments will occur at the start and end of one school year. Program implementers (<i>n</i> = 200) at schools will be randomized to assess the impact of the school-to-school mentoring strategy (vs. standard implementation) on HSRC’s acceptability, appropriateness, and feasibility (co-primary outcomes). Assessments will occur at the start, middle, and end of one school year. The assessment at the end of the school year will also include a concurrent mixed-methods approach (QUAL + QUAN), guided by the Consolidated Framework for Implementation Research (CFIR), to evaluate the school-to-school mentoring strategy. For quantitative outcomes, a generalized linear model framework will be used to evaluate HSRC and the school-to-school mentoring strategy.</p> Discussion <p>This study’s innovative dual randomized design allows for rigorous assessment of HSRC on effectiveness outcomes and the evaluation of a school-to-school mentoring implementation strategy on implementation outcomes. If both HSRC and the school-to-school mentoring strategy have their hypothesized effect, we will be well positioned to address cardiovascular and other chronic disease risk factors among youth using a scalable, widely used approach within one of the largest health educator networks in the country.</p> Trial registration <p>Clinicaltrials.gov on July 1, 2025 (NCT07079995).</p>