Historically, sexual and gender minority populations may have faced multiple Adverse Childhood Experiences (ACEs) and their utilization of preventive healthcare is low. However, sociocultural changes in attitudes and policies affecting sexual and gender minority populations signal their broader societal acceptance. We examined the prevalence of ACEs among sexual and gender minority populations belonging to Generation Z (those born between 1990-early 2000s) and their utilization of preventive healthcare to identify areas for health promotion. We used the Philadelphia Expanded ACEs questionnaire as well as questions about demographics and preventive healthcare use in a cross-sectional online survey design. The participants (n = 160) were chiefly female (n = 105, 65.6%) and bisexual (n = 51, 31.9%), while gender non-binary comprised 10.6% (n = 17). Most (93.75%, n = 150) participants reported three or more ACEs. ACEs were significantly associated with preventive healthcare use (p = 0.02). Higher prevalence of ACEs was associated with a 0.05 reduction in preventive healthcare utilization. Despite protective factors such as a comparatively advantaged background (based on their annual household income), health insurance, and college education, high ACEs, sexual orientation, and gender identity remained significantly associated with low utilization of preventive healthcare.