Objective: This systematic review examined the impacts of therapy dogs on the social and emotional wellbeing of K-12 students. Procedure: Five electronic databases (PsycINFO, Informit A+ Education, PubMed, Web of Science and ProQuest Dissertations & Theses Global) were searched to find English language, grey literature and peer-reviewed articles up to November 2020. Results: A narrative synthesis of 23 articles indicated that therapy dogs may enhance students' mood and positive emotionality, social and communication skills, confidence and their relationship with teachers. Inconsistently, other studies reported that therapy dogs may not enhance the social and emotional wellbeing of students. Conclusion: The current research is characterised by methodological limitations and an over-reliance on the perceptions of students and teachers. To enhance the quality and reliability of the evidence, future researchers are encouraged to adopt more rigorous methodologies with larger sample sizes and control procedures. It is also recommended that the perceptions of school leaders, other educational personnel and interdisciplinary health professionals are incorporated into future studies. This may contribute to a greater level of consensus in the educational sector about the impacts of therapy dogs on the social and emotional wellbeing of K-12 students.