Online games lately have become very popular among Indonesians, especially children to adolescents. This is evidenced by Winsen Sanditaria's research conducted in Sumedang, which stated that out of 71 respondents there were 62% of addictions playing online games. It is undeniable also in the current era that smartphones have been mushrooming in public audiences and even early childhood children have been held by smartphones for their daily lives. Especially children who like to play online games. Thus the intensity of children playing online games will be increasingly often done. With children often playing games, it will affect the child's religious side. This study aims to find out whether there is an influence of online game addiction on the level of child religiosity. This study uses a descriptive quantitative approach, through data collection techniques with observation, questionnaires, interviews and documentation. The population in this study were students in grades IV and V of Muhammadiyah Tamantirto Kasihan Elementary School Bantul in 2018/2019 school year. The sample in this study were 61 respondents who the researcher chose through simple random sampling technique. Analysis of the data that the researchers used were descriptive analysis, correlation test, simple linear regression and t test using SPSS 25 software. The results showed that there was a significant influence between online game addiction and the level of religiosity with partial test results showing tcount of -2.93 with Significance of 0.004 is smaller than 0.05. So it can be concluded that online game addiction has a negative relationship. Based on the calculation of the variable x (online game addiction) it was concluded that the average value for high classification with the number of 15 respondents had an average yield of 22.80 with a percentage of 24.6%. Then on the calculation of the variable y (level of religiosity) concluded that the average value for high classification with the number of 46 respondents had an average value of 22.46 and a percentage of 75.4%.