AimsTo evaluate and synthesize psychometric properties of the MOS‐SSS and to identify quality versions of MOS‐SSS for use in future research and practice.DesignA psychometric systematic review.Data SourcesArticles about the translation, adaptation, or validation of the MOS‐SSS in Medline, PubMed, CINAHL, and Web of Science and their reference lists published before 11 November 2022.Review MethodsThe review followed the Consensus Standards for the Selection of Health Measurement Instruments guidelines.ResultsThe review included 35 articles. Eleven versions of MOS‐SSS (3, 4, 5, 6, 8, 12, 13, 16, 18, 19, and 22 items) have been validated in various populations and 13 languages. Of 14 studies developing a translated version of MOS‐SSS, four studies performed both an experts' evaluation of content validity and a face validity test; two studies reported translation evaluation in the form of a content validity index. Of 35 studies, six performed both exploratory factor analysis and confirmatory factor analysis for structural validity; hypotheses and measurements for construct validity testings were often not clearly stated; two examined criterion validity; and four assessed cross‐cultural validity. Internal consistency reliabilities were commonly examined by calculating Cronbach's alpha and reported satisfactory. Five studies analysed test–retest reliabilities using intra correlation coefficient. Methodological concerns exist.ConclusionThe English 19‐item, Farsi Persian 19‐item, and Vietnamese 19‐item versions are recommended for future use in research and practice. Italian 19‐item and Malaysian 13‐item versions are not recommended to be used in future research and practice. All other versions considered in this review have potential use in future research and practice. Proper procedures for developing a translated version of MOS‐SSS and validating the scale are recommended.ImpactThe review identified quality versions of MOS‐SSS to measure social support in future research and practice. The study also indicated methodological issues in current validation studies. Application of the study findings and recommendations can be useful to improve outcome measurement quality and maximize the efficiency of resource use in future research and practice.No Patient or Public ContributionThis systematic review synthesized the evidence from previous research and did not involve any human participation.