Pediatric trials are possible through voluntary participation of children, youth (age less than or equal to 18 years), and their families. Despite important arguments for trialists to provide trial progress or results, and evidence that participants desire it, this information remains rarely shared with youth and their families. Little guidance exists on how trialists can best communicate trial results back to participants and their families. Guided by Liabo et al.'s framework, we describe how we developed a pediatric-specific, "plain language summary" clinical trial results template called CommuniKIDS with an adult patient partner, family partner (parent), youth advisors, and parent advisors, taking into account their unique knowledge needs and preferences. Involvement of a patient partner, a family partner, youth advisors, and parent advisors in the development of CommuniKIDS was critical to create a clinical trial results template that is useful and relevant to its end-users. To our knowledge, CommuniKIDS is the first to meaningfully engage youth and parents as advisors and partners in developing a plain language summary results template for pediatric trial participants and their families. Our experience of co-developing CommuniKIDS demonstrates that meaningful PPI can be achieved in trial results communication and knowledge translation practices. This report provides resources for those seeking to involve youth and families in their initiatives and in meaningfully sharing trial results.