Increasing evidence suggests that different dimensions of early-life adversity may be associated with unique neurodevelopmental mechanisms and behavioral outcomes. We sought to characterize the underlying dimensional structure of co-occurring adverse experiences among a subset of youth (ages 9-10) from the Adolescent Brain Cognitive Development (ABCD) Study (N = 7,115), a community sample of youth in the United States. We identified 60 environmental and experiential variables that reflect adverse experiences. Exploratory factor analysis identified 10 early-life adversity dimensions of co-occurrence, corresponding to conceptual domains such as caregiver substance use and biological caregiver separation, caregiver psychopathology, caregiver lack of support, and socioeconomic disadvantage / neighborhood lack of safety. These dimensions demonstrated distinct associations with internalizing problems, externalizing problems, cognitive flexibility, and inhibitory control. Non-metric multidimensional scaling characterized qualitative similarity among the 10 identified dimensions. Results supported a nonlinear three-dimensional structure representing early-life adversity, including continuous gradients of “perspective”, “environmental uncertainty”, and “acts of omission/commission”. Our findings suggest that there are distinct dimensions of early-life adversity in the ABCD sample at baseline, and the resulting dimensions may have unique implications for neurodevelopment and youth behavior.