Traumatic events have significant negative impacts throughout one's life. We aimed to comprehensively examine the early associations between traumatic events and suicidality among adolescents. In a cross-sectional sample of 260,423 adolescents in Deyang, China in September 2021, we assessed individual traumatic events, cumulative types, and patterns, alongside suicide risk scores and ideation, attempts, or plans. Linear and Poisson regression models adjusted for demographic confounders evaluated the association. Robust associations existed between interpersonal violence-related traumatic events and higher suicidality, with physical abuse demonstrating the strongest correlation. Moreover, suicide risk scores displayed a clear trend, indicating a progressively stronger association with suicidality as cumulative traumatic event types increased. Four distinct traumatic patterns emerged, including low traumas, high physical abuse, high death/serious injuries of a loved one, and multiple traumas, with the latter showing the strongest association with suicidality. Notably, the stratified analysis showed these associations were more pronounced in females, urban residents, only children, left-behind children, and those aged 13–15, while weaker in participants from families with intact parental relationships and middle socioeconomic status. Understanding the role of demographic factors and traumatic patterns in identifying at-risk youth can enable early detection and targeted interventions for suicide-related concerns.