The aim of this study is to develop a reliable and valid scale tool that measures social media jealousy in romantic relationships of individuals who have had and are currently living in a romantic relationship. For this purpose, in the process of creating a candidate scale form; "qualitative steps" (focus group interviews, essay printing, literature scale scanning) and "quantitative steps" (validity and reliability analysis) were used. Items with content validity rate below .80 after expert evaluations were removed from the 57-item form and 53 items remained. The 53-item and five-point likert-type trial scale form was applied to 417 individuals between the ages of 18-56 who had or had a romantic relationship. The basic assumptions of Explanatory Factor Analysis (EFA) have been tested; As a result of EFA, a structure consisting of a total of 21 3-dimensional items, namely "Restrictive and Controlling Attitude", "Skeptical and Observant Attitude", and "Respect and Trust in the Field of Social Media", was obtained. In order to examine the psychological construct validity of Social Media Jealousy in Romantic Relationships Scale; With the final form consisting of 21 items formed after EFA, data were collected again with 332 individuals; Before CFA, assumptions were tested and confirmatory factor analysis (CFA) was performed. As a result of DFA; When the standardized load values of the sub-dimensions, the estimated error variances for the variables, the T values of all items and the goodness of fit of the model were examined, it was found that the 3-factor structure of the scale consisting of 21 items was confirmed as a model. When the convergent validity, divergent validity and combining reliability values of the scale after CFA are examined, it is seen that the values are suitable for the criteria in general. Finally; Cronbach alpha internal consistency coefficient; .922 for the whole scale, .878 for "Restrictive and Controlling Attitude", .881 for "Skeptical and Observant Attitude", and .878 for "Respect and Trust in Social Media". When all these findings are examined; It was concluded that it is a reliable and valid scale for measuring social media jealousy in romantic relationships.