To help guide school mental health policy and practice, we evaluated patterns of mental health help-seeking across lifetime adversity among sixth-grade adolescents. An ethnically/socioeconomically diverse sample of sixth-graders (N = 751) self-completed assessments of help-seeking and indicators of lifetime adversities: violence victimization, poverty, parent loss/divorce, mental illness/substance abuse at home, and stressors related to social identity. Logistic regression models adjusting for family/personal factors examined adversity factors on help-seeking outcomes overall and across subgroups with mental health perceived problems and high-symptoms. Overall, odds increased between perceived problem and formal service use, poverty and formal service/school counselor use, and high-symptoms/victimization and talking to a friend (p < 0.05). Among those with perceived problems, odds increased between mental illness/substance abuse at home and formal service use, victimization and talking to a friend, and poverty and school counselor use (p < 0.05). Among those with no mental health problems, odds increased between victimization and formal service/school counselor use, and poverty and formal service use (p < 0.05). No significant patterns were observed in the high-symptom subgroup. Understanding how adversity shapes help-seeking can help guide school mental health policies and practices. Study findings point to areas for expansion of supports for students with adversity to create a mental health safety net and help mitigate future risk.