Communication is essential to physiotherapy practice. While verbal communication has been a primary focus in research, less is known about body communication. Body communication refers to communication achieved by means other than words, such as touch, eye contact, prosody, and proxemics. This review aims to provide detailed knowledge of the roles and functions of body communication in physiotherapy practice and identify areas for future research. We undertook a systematic search and thematic synthesis of published qualitative literature in October 2022. Four databases were searched with results screened to identify articles providing insight into the roles and functions of body communication. Quality appraisal of included studies was completed. Thematic synthesis was used to generate findings. Thirty-three studies met the inclusion criteria. Four themes were constructed to reflect the roles and functions of body communication in physiotherapy practice: conveying the physiotherapist’s attention and interest; enabling patients to contribute to care; guiding physiotherapy intervention through bodily dialogue; and building the therapeutic relationship. The findings demonstrate how body communication shapes the therapeutic process and how sensitive and responsive body communication supports a more reciprocal and person-centred approach to care. Research is needed to obtain more in-depth and nuanced accounts of body communication to support the clinical application of findings.