Purpose: This study investigated smartphone usage time and related factors in multicultural adolescent smartphone users. Methods: Data were obtained from 1,499 subjects aged 13 to 18 years who participated in the 18th Korea Youth Risk Behavior Web-based Survey (KYRBS) conducted in 2022. A composite sample analysis performed. Results: The average daily time spent on a smartphone was 1.9 hours. Multiple sample logistic regression analysis revealed the factors that in- fluence smartphone usage and these included the female gender, lower academic achievement, and lower parental edu- cation as general characteristics. Smartphone usage was also found to play a role in health behaviors with high usage observed among those who did not recover after sleep and engaged in alcohol consumption. In terms of mental health, students with high levels of perceived stress, and those who experienced feelings of sadness or hopelessness reported higher smartphone usage. Conclusion: To promote healthy digital habits among multicultural adolescents, it is necessary to develop tailored programs considering each of the above mentioned factors. These programs should involve collabo- ration among individuals, families, and schools. The findings from this study can serve as a foundation for designing poli- cies and programs aimed at managing and moderating smartphone use among multicultural adolescents.