Purpose: This systematic review identified and synthesized published research articles, written in Japanese, on the clinical effectiveness of a broad range of nonpharmacological interventions for school-age children who stutter. Method: A systematic review of Japanese literature published between January 1, 1980, and July 7, 2020, reporting interventions for school-age children who stutter, was carried out through a search of two databases (CiNii Article database and Japan Medical Abstract Society database) using the key words "stuttering" and "school-age" or "child" or "primary school students" or "children" or "school child" in Japanese. To be included in the review, the articles must report studies where data were subjectively reported by clinicians, where school-age participants were treated for developmental stuttering, where participants received interventions conducted by clinicians, and where quantitative outcomes (pre- and/or posttreatment) were measured; and they must be published in Japanese. Results: Forty articles met all the inclusion criteria. Most articles adopted a case series or single-case study design. A total of 179 intervention programs were identified from all the articles and broadly classified into speech therapy, psychological therapy, interventions for modifying the child's environment, and others. Conclusions Our systematic review provided a broad overview of the treatments used for school-age children who stutter in Japan. Future research should focus on gathering more reliable, systematic, and rigorous evidence to establish the effectiveness of stuttering treatments for school-age children and thereby develop evidence-based practices.