Reflective supervision and consultation (RS/C) is regarded as best practice within the infant/early childhood mental health field. Benefits of RS/C on the early childhood workforce and children and families have been demonstrated through case studies, conceptual pieces, and individual research studies. However, findings across studies have not been summarized using gold‐standard methodology, thus the state of existing empirical support for RS/C is unclear. This systematic review examined the collective evidence for RS/C across diverse early childhood‐serving programs. Electronic databases were searched to identify studies investigating associations between RS/C and professionals’ reflective capacity and well‐being, child/family outcomes, and implementation factors. Twenty‐eight papers were identified. Studies showed positive associations between RS/C and early childhood‐serving professionals’ reflective capacity and well‐being, with qualitative studies reporting more consistent results than studies using quantitative methods. Many methodological limitations were identified, including incomplete reporting of study designs and participant characteristics, variability in outcome measures, and lack of randomization and comparison groups. Furthermore, few studies examined child and family outcomes. Therefore, while RS/C shows great promise, it was difficult to ascertain its overall effectiveness from an empirical standpoint. Establishing RS/C as an empirically supported approach will be possible with more rigorous research.