Purpose: For speech-language pathologists (SLPs) working in schools, outcome measurement is an important element of practice, enabling us to evaluate the efficacy of our service provision and guiding future decision making, funding, and resource allocation. When selecting outcomes to measure, it is helpful to consider both the level at which change may be occurring and the extent or impact of that change. The primary aim of this review was to identify the outcomes measured in intervention studies for school-aged children with speech, language, and communication difficulties (SLCD) using the International Classification of Functioning, Disability and Health to classify the outcomes. A second aim was to identify tools used in research studies to measure the outcomes. Method: A systematic search of five databases was undertaken to identify papers reporting outcomes for school students who had received intervention targeting SLCD. Articles written in English and published between January 2000 and August 2021 were included. The Taxonomy for Categorizing Outcome Measures for SLCD was created to enable a review of outcomes and measurement tools. Results: There were 125 papers included in the final review. Most papers (n = 109, 87.2%) reported on studies that included outcome measures that captured changes at Body Function level, while approximately half captured Activity-level change. Only 24 (19.2%) explored changes at Participation level. Conclusions: Change at the Body Function or Activity levels does not always reflect change at the Participation level. Measuring outcomes at the Participation level enables SLPs to determine the real-world impact of the adjustments they have recommended or the intervention they have provided. However, in order to measure outcomes at the Participation level, we need the tools for capturing those changes for school-aged students with SLCD.