BackgroundChildren who spent time in non-parental care report poor outcomes in many aspects of their later lives on average, but less is known about differences by ethnicity. We examined whether the health, socioeconomic, family, and living arrangements of adults who had been in non-parental care across the first three decades of adult life varied by ethnicity (White, Black, South Asian).MethodsWe used longitudinal data from the Office for National Statistics Longitudinal Study (LS). Participants were aged<18 years and had never been married at baseline of each census year from 1971-2001 (n= 672,648). Separately for each adult follow-up age group (20 to 29; 30 to 39; 40 to 49), multi-level regression models were used to compare socioeconomic, family, and living arrangements by non-parental care and ethnicity interactions.ResultsAdverse adult outcomes following an experience of non-parental care were conditional on the interaction of non-parental care with ethnicity, mainly in the socioeconomic domain. More negative adult outcomes among the ethnic minority groups following non-parental care in childhood were not found consistently: for some outcomes the White group had poorer outcomes; South Asian individuals had better outcomes than Black people who had been in non-parental care but the within-ethnic group differences were smaller for Black than for South Asian children; and findings differed across the lifespan from early to mid-adulthood as work and family lives evolved.ConclusionWe uncovered much complexity, with minority ethnicity moderating the non-parental care to adult outcomes relationship in both positive and negative ways. Previous work that has sampled children from the population with experience of non-parental care provides incomplete evidence from which to base policy decisions.