Background: Social citizenship means creating a situation in which everyone can develop their full potential. Objectives: This study aimed to determine the social citizenship index with its various dimensions in selected countries. Methods: This study used a mixed-methods approach consisting of two phases. In the first phase, social citizenship items were extracted based on a systematic review of previous studies and interviews with experts using direct content analysis. In the second phase, the standardized index was assessed by performing the validity and reliability tests. To combine the dimensions, their values were standardized using the Z score. To analyze the data, factor analysis and normality tests were used. Results: The social citizenship index was categorized into four main dimensions, including health and education, livelihood, economic-political prosperity, and open society. In this study, 125 countries were categorized based on the Social Citizenship Index. The selected countries were classified into three categories based on the opinions of the research group and the cutting point of statistical quartiles: high (32 countries), medium (62 countries), and low (31 countries). Conclusions: It can be concluded that the social citizenship index with four main dimensions and 26 variables is a new tool that allows countries to be compared in the areas of providing welfare services to their citizens.