This study examined whether poverty (neighborhood and household) was associated with future health or life satisfaction outcomes and whether the association operated through social support (adult support at home, adult support at school, peer belonging), or differed by the immigration background (nonimmigrant family or immigrant family) of the family. This study utilized a retrospective, longitudinal, population-based cohort that included self-reported survey data from the Middle Years Development Instrument (MDI) completed by children at age 9 and age 12, linked to administrative records. Participants included 5906 children in British Columbia, Canada. Neighborhood and household poverty were observed at age 8. Social support from adults and peers was self-reported at age 9. Outcomes (overall health; life satisfaction) were self-reported at age 12. Adjusted multi-level multiple linear regression analyses and parallel mediation analyses were utilized. The interaction between poverty exposure and immigration background was also examined. Exposure to either poverty type was associated with lower levels of life satisfaction and overall health at age 12, though household poverty appeared to be associated with lower outcomes in comparison to neighborhood poverty. The indirect effects of poverty on outcomes appeared to operate primarily through adult support at home and peer belonging. Children in immigrant families had a larger negative association between neighborhood poverty and life satisfaction. Household poverty had a larger negative association to outcomes in comparison to neighborhood poverty. The association of poverty to outcomes differed by immigration background and operated partially through adult support at home and peer belonging.