Background: To help improve outcomes for children with cerebral palsy (CP), ankle–foot orthoses (AFOs) and supramalleolar orthoses (SMOs) are prescribed. However, it is not clear why one intervention is prescribed over the other. Objectives: To explore the rationale for prescribing AFOs and SMOs in children with CP and its link to the choice of outcome measure used. Study design: Narrative review. Methods: Six databases were searched (eg, Medline) and data extracted from articles that met the inclusion criteria. Data describing the participant demographics, type of orthosis, and outcome measures used were summarized to provide context for the different rationale for orthotic prescription that were thematically analyzed. Discussion: Forty-seven articles were included. Participants were aged 9 ± 2 years, 59% were male, 79% had diplegia, and 38% were classified as Gross Motor Function Classification System level I. All studies included a rationale for prescribing AFOs that, in most cases, reflected the outcome measures used. These rationale statements were synthesized into 5 specific themes (e.g., reduced energy expenditure and metabolic costs). By comparison, 5 of these studies described the rationale for providing SMOs, and of those that did, most of the rationale statements were nonspecific. Conclusions: A large and contemporary body of literature describes the rationale for prescribing AFOs for children with CP. There are opportunities for future research that clearly articulates the rationale for prescribing SMOs for children living with CP and to focus the rational for orthotic intervention on the real-world challenges that are most important to children living with CP, such as the ability to participate among peers.