Abstract: Childhood conditions of inattention and disruptive behavior, such as Attention-Deficit/Hyperactivity Disorder (ADHD) and Oppositional Defiant Disorder (ODD), are prevalent but undertreated worldwide. One promising solution is harnessing digital technology to enhance school clinician training and ADHD/ODD intervention programs. We conducted a school-clustered randomized controlled trial of CLS-R-FUERTE: a program featuring training/consultation for school clinicians to deliver a six-week intervention comprised of weekly parent and student skills groups, as well as support teachers’ classroom management in the form of a Daily Report Card, all facilitated by electronic program manuals/materials and videoconferencing. A total of N = 163 (n = 6–8 students/school [ages 6–12] and their parents, teachers, and school clinicians) participated across eight public schools in Sinaloa, Mexico. We randomly assigned four schools to receive CLS-R-FUERTE immediately and four schools to receive school services as usual. We compared groups post-treatment on parent- and teacher-rated ADHD/ODD and impairment. We observed the program implementation in vivo, tracking trainer and school clinician program fidelity, as well as participant attendance and adherence, to evaluate feasibility. We also collected participant ratings of satisfaction and usability on the System Usability Scale to evaluate acceptability. Our CLS-R-FUERTE trial demonstrated high rates of program feasibility and acceptability comparable to prior in-person program trial findings. Students receiving CLS-R-FUERTE showed greater improvement in parent- and teacher-rated ADHD, as well as parent-rated ODD and impairment, compared to students receiving school services as usual. Results support the utility of global digital mental health programs training school clinicians to implement ADHD/ODD interventions, which have the potential to increase evidence-based treatment access and uptake across worldwide contexts.