The hypothalamic pituitary adrenal (HPA) axis is a primary neuroendocrine system posited to mediate the associations between early life stress and long-term deleterious psychological and physical health outcomes. The effects of early life adversity on HPA axis functioning have been well-documented in primarily White samples, with statistical advances allowing researchers to isolate latent trait cortisol as a stable indicator of HPA axis functioning to account for day-to-day influences on diurnal cortisol patterns. However, directional associations have been mixed depending on developmental stage, demographic composition, and methodological differences across studies. The few studies of early adversity and HPA axis functioning in Hispanic/Latino/a/x samples demonstrate complex interactions between cultural processes and adversity in predicting HPA axis output. Further, nascent literature has isolated the cognitive, meaning-making, and prosocial skills involved in ethnic racial identity (ERI) and its subconstructs of exploration, resolution, and affirmation as promotive during the adolescent stage of development in Latinx youth. Such skills might better prepare youth for neurobiological stress regulation after adversity. To my knowledge, no study has examined whether ERI plays a protective role against the effects of early adversity on trait-level indicators of the HPA axis during adolescence, despite the particularly high rates of cumulative exposure to early life adversity in Latinx youth as compared to White counterparts. Guided by adaptive cultural resilience theories, this study of 197 socioeconomically diverse Latinx older-adolescents aimed to leverage recent findings of stable trait indicators of cortisol output to 1) identify consistent directional markers of the effects of early life adversity on latent trait cortisol in a Latinx sample and 2) elucidate the degree to which ERI might act as a promotive feature for HPA axis levels and protective factor against cumulative early life adversity. Confirmatory factor analyses identified a theory-driven model as an adequate measure of latent trait cortisol. Greater exposure to early adversity predicted lower latent trait cortisol, but ERI demonstrated neither protective nor promotive effects. The present study reifies that early adversity exposure has deleterious effects on trait-level HPA axis functioning, but identifying sources of cultural resilience among Latinx youth remains critical for the future of health equity.