The purposes of this study were to compare the use of contraception by monocultural and multicultural adolescents and identify the multidimensional factors in an ecological model. This study was cross-sectional design with a secondary data analysis using national data from the 2018 Korea Youth Risk Behavior Survey, including 3,031 participants (81 multicultural and 2,950 monocultural adolescents with sexual activity). The monocultural adolescents reported significantly higher rates of contraceptive use (61.66%) than multicultural adolescents (39.39%, p < 0.001). Monocultural adolescents' contraception use was significantly associated with intrapersonal factors (gender, drinking, and using substances) and school factors (school location, grade, and sex education). School factors also associated with multicultural adolescents' contraception use. To promote contraception use by multicultural adolescents with sexual activity, sex education should be tailored to meet specific cultural needs. In addition, risky behavior prevention should be part of comprehensive health promotion and sex education for monocultural adolescents.