This study examined neighborhood-level associations among child opportunity, opportunity inequality, racial composition, and frequency of youth psychiatric emergency responses in the nation’s largest county mental health system. Geo-coded data on mobile crisis response (MCR) services, neighborhood opportunity, and child racial/ethnic population were extracted for youth in Los Angeles County between 2016 and 2019 and examined in descriptive and Poisson regression analyses. Black and Multiracial youth were overrepresented in MCRs relative to their county representation. Larger concentrations of child racial/ethnic-minority populations, lower levels of opportunity, and higher levels of opportunity inequality were each associated with higher frequency of MCRs at the zip code level. In adjusted multivariate analyses, Black youth population density and higher education opportunity inequality predicted higher incidence of MCR response. Findings may reflect actual racial disparities in youth mental health need and/or institutional racial biases embedded within community responses to youth behavior.