To examine associations among neighbourhood food environments (NFE), household food insecurity (HFI) and child’s weight-related outcomes in a racially/ethnically diverse sample of US-born and immigrant/refugee families.

This cross-sectional, observational study involving individual and geographic-level data used multilevel models to estimate associations between neighbourhood food environment and child outcomes. Interactions between HFI and NFE were employed to determine whether HFI moderated the association between NFE and child outcomes and whether the associations differed for US-born v. immigrant/refugee groups.

The sample resided in 367 census tracts in the Minneapolis/St. Paul, MN metropolitan area, and the data were collected in 2016–2019.

The sample was from the Family Matters study of families (n 1296) with children from six racial/ethnic and immigrant/refugee groups (African American, Latino, Hmong, Native American, Somali/Ethiopian and White).

Living in a neighbourhood with low perceived access to affordable fresh fruits and vegetables was found to be associated with lower food security (P < 0·01), poorer child diet quality (P < 0·01) and reduced availability of a variety of fruits (P < 0·01), vegetables (P < 0·05) and whole grains in the home (P < 0·01). Moreover, residing in a food desert was found to be associated with a higher child BMI percentile if the child’s household was food insecure (P < 0·05). No differences in associations were found for immigrant/refugee groups.

Poor NFE were associated with worse weight-related outcomes for children; the association with weight was more pronounced among children with HFI. Interventions aiming to improve child weight-related outcomes should consider both NFE and HFI.