Adolescents are most likely to receive mental health services in schools compared to other settings; however, few studies have examined barriers to mental health help seeking at school for ethnic minority adolescents. The current mixed-methods study utilized surveys and semi-structured interviews to explore the mental health literacy (MHL), stigma toward mental illness, and perceived barriers toward help seeking at middle or high schools among 55 adolescents (81.8% female; 50.0% Asian-American, 44.6% Latinx-American, 5.4% Asian/Latinx bi-racial; M age = 17.13 years, SD = 2.33). Participants' MHL was assessed using case vignettes that depicted adolescents with symptoms of depression or bulimia. Overall, 83.9% of participants correctly recognized depression and 57.1% correctly recognized bulimia from the vignettes. Stigma correlated with perceived helpfulness of the formal service providers (r = - 0.37, p < 0.01). Qualitative analysis of participant interviews revealed important knowledge, attitudinal, and practical barriers that inhibit Asian- and Latinx-American adolescents from seeking help for mental health problems at school. The current work has implications to assist school personnel and mental health providers in understanding and reducing barriers to help seeking for Asian- and Latinx-American adolescents.