Face-to-face pain management programs demonstrate positive clinical outcomes in the chronic pain population by improving pain intensity and attitudes, depression, and functional disability scores. The effects of this modality carried out online is less known, particularly in subgroups of chronic pain. This systematic review assessed the effects of online pain management programs in chronic, widespread musculoskeletal conditions on pain measurements (intensity, interference, coping, and catastrophizing), health-related quality of life, depression, and anxiety scores immediately post-intervention. Five electronic databases (Embase, Medline, CINAHL, Scopus, and PEDro) were searched with 3546 studies identified. Eighteen randomized controlled trials fulfilled the inclusion criteria. Included studies had moderate methodological quality (using the Effective Public Health Practice Project (EPHPP) quality assessment tool) but high risk of bias (using the revised Cochrane risk-of-bias tool for randomized trials (RoB 2)). There were significant improvements in pain intensity (11 studies, 1397 participants, SMD -0.30, 95% CI -0.50 to -0.10, p = 0.004), health-related quality of life (eight studies, 1054 participants, SMD 0.41, 95% CI 0.08 to 0.75, p = 0.02), and depression (nine studies, 1283 participants, SMD -0.32, 95% CI -0.55 to -0.08, p = 0.008). However, effect sizes were small and did not meet their respective measure’s minimal clinically important change score. Guided interventions (regular interaction with an instructor) appeared to be superior to self-completed interventions. Future research should standardize outcome measures for assessing pain, use active control groups, and analyze other outcome measures such as cost and long-term effects. This study was registered with Prospero on August 15, 2021 (CRD42021267565).