Background: The present study aims to determine the reliability and validity of the Positive Mental Health Literacy Scale in the Turkish language. Methods: The sample of the present methodological study included 457 adolescents. The data were collected between February 10, 2019, and May 31, 2019, with a sociodemographic data form and the Positive Mental Health Literacy Scale. The scale was first translated to the Turkish language, expert opinion was obtained, and a pilot scheme was conducted. The content validity index was employed to test the validity of the scale, confirmatory and exploratory factor analyses were conducted to test the construct validity, item analysis was conducted to test the reliability of the scale, Cronbach’s alpha analysis was employed to determine internal consistency, and the test–retest scores were compared to determine time invariance. Results: The scale is unidimensional. The content validity analysis of the scale was 0.97. Scale item loads varied between 0.56 and 0.72 based on the confirmatory factor analysis. The Cronbach’s alpha coefficient of the scale was 0.87, and the test–retest score was intraclass correlation coefficient = 0.739 (P <. 001). The mean participant score on the positive mental health literacy scale was 2.9 (SD=0.9). Conclusion: The validity and reliability findings in the study that was conducted to adapt the Positive Mental Health Literacy Scale to the Turkish language revealed that the scale could be used to measure the mental health literacy of adolescents. The Turkish version of the scale could be used in programs that aim to identify positive mental health literacy levels of adolescents in Turkish society.