Purpose <p>There is a dearth of high-quality, efficient, and change-sensitive measurement tools for capturing social communication for young children with autism. The current study sets out to develop such a measure using best practices in patient-reported measure development.</p> Methods <p>The Questionnaire for Social Communication in Young Autistic Learners (Q-SoCiAL) was developed in four phases: (1) construct definition and item generation using information from literature review and focus groups with parents, teachers, and experts; (2) item refinement via cognitive interviewing with parents and teachers of autistic children; (3) item selection and evaluation of structural validity using data from parents of autistic (<i>n</i> = 330) and neurotypical (<i>n</i> = 401) children; and (4) evaluation of external validity, including known groups comparisons (autistic vs. neurotypical children) and convergent/divergent validity evidence.</p> Results <p>Preliminary analyses, cognitive interviewing, and expert review led to a final instrument containing 46 items appropriate for use with children who use more than 10 spontaneous words. Factor analysis on a sample of 330 children suggested a unidimensional structure. Internal consistency, test-retest reliability, and cross-rater consistency were very high. Q-SoCiAL scores correlated as expected with several clinical and demographic variables in the autism group.</p> Conclusion <p>This new measurement tool fills an important gap in the field and has the potential to improve social communication measurement in clinical practice and research.</p>