Adolescents from ethnoracially minoritized backgrounds increasingly report high rates of attempted suicide, trauma exposure, and limited access to mental healthcare services. However, less is known regarding their use of services across different youth-serving systems. This study examines the associations and interactions between self-injurious thoughts and behaviors (SITBs), race/ethnicity, and service sector utilization (mental healthcare, general healthcare, school, and social services) among a sample of trauma-exposed and treatment-seeking adolescents. Participants were treatment-seeking adolescents (N = 4406) ages 12-17 from the National Child Traumatic Stress Network Core Data Set who had available data for SITBs, race/ethnicity, services utilized, and other key variables. Mixed effects logistic regression was used to examine main and interactive effects for whether adolescents' race/ethnicity and SITBs were associated with service utilization in each of the identified service sectors. SITBs were associated with adolescents' utilization of mental healthcare (OR = 1.38 p < 0.001), general healthcare (OR = 2.30; p < 0.001), and school services (OR = 1.38 p < 0.001). NH Black adolescents reporting SITBs were less likely to use mental health services than other NH Black youths (OR = 0.53; p = 0.004). Hispanic adolescents reporting SITBs were more likely to utilize healthcare services than other Hispanic youths (OR = 1.51; p = 0.039). Trauma-exposed adolescents reporting SITBs are more likely to utilize mental healthcare, general healthcare, and school-based services than other trauma-exposed adolescents. However, NH Black adolescents experiencing SITBs may face additional barriers to utilizing mental healthcare services. Findings can be used to develop nursing practices and policies to address barriers faced by adolescents reporting SITBs.