Objective: There has been an ongoing mental health crisis among sexual and gender minority (SGM) populations. This continues amidst rising population-level depression and suicide rates, especially among students in higher education. This work aims to understand changes in SGM student mental health over time. Participants: N = 483,574 responses to the Healthy Minds Study (2007C2022) were examined from 18 to 35-year-old U.S. college and university students. Methods: Linear and logistic regressions were used to examine associations between SGM identity and mental health. Mediation and structural equation modeling were used to examine potential links among risk factors. Results: On average, ∼18% of students identified as SGM, which included a 6-fold increase in SGM self-identification across this 15-year period. Depression rates increased over time; ∼12% of students reported major depression. SGM students were 3.18 times (z = 111.16, p < .001) more likely to report depression than non-SGM students (26.85% vs. 8.53%). Disproportionate discrimination and lack of school belonging partially explained SGM disparities in depression. SGM students were twice as likely to utilize therapy (z = 115.42, p < .001) but half as likely seek help from family (z = 55.48, p ≤ .001). Conclusions: Academic institutions must take concrete steps to reduce barriers mental health care, combat discrimination, and bolster community belonging and interpersonal support for SGM students.