Purpose: Understanding the enablers of and barriers to physical activity (PA) participation in people with fibromyalgia (PwF) is an essential first step to developing effective PA interventions. This systematic review examined correlates of PA across the socio-ecological model (i.e., intra-personal, inter-personal, environmental, and policy level) in PwF. Materials and methods: PubMed, Embase, and CINAHL were searched from inception until 12 July 2022. Keywords included “physical activity” or “exercise” and “fibromyalgia” or “fibrositis.” Summary coding was used to quantify the PA correlates. Results: Out of 74 PA correlates retrieved from 39 articles (n = 9426), co-morbid depression and higher pain intensity were found to be consistent (i.e., reported in four or more articles) barriers to PA in PwF, while higher self-efficacy and better endurance were found to be consistent enablers to PA. Despite the abundance of evidence for the PA benefits for PwF, we only found consistent evidence for PA correlates at the intrapersonal level. Conclusions: Health professionals should consider mental and physical health barriers when promoting PA in PwF. There remains a need to better understand social, environmental, and policy-related factors associated with PA participation in PwF.