The Handwriting Heroes Program (HHP) is designed for school-based occupational therapists (OTs) for the implementation of structured interventions to promote the development of handwriting legibility. The interventions are intended for children with identified handwriting weaknesses. The HHP uses evidence-based research to describe the components of the manual, develop accompanying resources to the program, and determine interventions within the program’s treatment sessions. This evidence also supports the rationale behind the development of the program, including how the program relates to the Common Core State Standards Initiative (CCSS). This paper discusses the theoretical design of the HHP using relevant models of practice, such as the Model of Human Occupation (MOHO). It also outlines frames of references, guidelines, and frameworks within the description of the program, including those provided by the American Occupational Therapy Association (AOTA). This paper describes the pracitce implications, implementation, and future implications for school-based OTs to advance occupational therapy (OT) practice skills for the development of occupational performance in a child’s education.