The motivation behind this research is to examine how much influence the online mobile legend game has on the mental health of students at SMPN 1 Kota Baru. This study uses a quantitative methodology with ex-post facto research techniques. This research was conducted at SMPN 1 Kota Baru on May 20 to June 6 2022. The population was all Grade VIII students at SMPN 1 Kota Baru, totaling 427 people. The population in this study was taken using the snowball sampling method, consisting of 30 individuals consisting of 21 men and 9 women. The instrument uses a mobile legend online game questionnaire and a mental health questionnaire. The examination method used in this exploration is a linear regression equation. The consequences of this study show the extent to which sig. <0.05 and a guarantee coefficient of 0.000 which indicates that the effect of playing mobile legend online games on the mental health of students at SMPN 1 Kota Baru is 90.8% while 9.2% is influenced by different variables. The conditions set are = 4,923 + 1,000 X, so that the mental health of students will decrease as the strength of playing online mobile legend games increases by 1,000.