Abstarct: The purpose of this research was to investigate the effect of physical literacy on the mental health of the elderly with the mediating role of sports participation motivation. The method of the current research was descxriptive-correlative in nature and cross-sectional in terms of time. The statistical population of the study was all the elderly people of Shahrood City, and 236 people were selected as a sample using the random sampling method. The research tools were 3 standard physical literacy questionnaires by Liu et al. (2022), Keyes et al.'s mental health questionnaire (2002), and Desi and Ryan's (2004) sports participation motivation. Structural equations with variance-oriented approach were used to check research hypotheses. SPSS23 and Smart-PLS 3.2.8 software were used for data analysis in the present study. . The results of the research showed that physical literacy and the motivation to participate in sports have a positive and significant effect on the mental health of the elderly. Also, physical literacy has a positive and significant effect on sports participation. The mediating role of sports participation motivation in the relationship between physical literacy and mental health of the elderly was confirmed. According to the results of the research, it is possible to strengthen the level of physical literacy and the motivation to participate in sports in order to increase their mental health by carrying out psychological and sports planning and counseling.