The construct validity of the Family Involvement Questionnaire–Short Form (FIQ‐SF) was examined in an independent sample of ethnically and linguistically diverse low‐income families (N = 498) enrolled in an urban Head Start program in the Southeast. A series of exploratory and confirmatory factor analyses replicated the three‐factor structure identified in initial validation studies with Northeast samples: home‐school conferencing, home‐based involvement, and school‐based involvement. Findings from multiple group confirmatory factor analyses provided evidence that the three‐factor structure was invariant across family ethnicity. multivariate analyses of variance also confirmed hypothesized mean differences on FIQ‐SF dimension scores across family demographic variables such as caregiver ethnicity, primary home language, caregiver education, employment, and marital status. Findings replicate and extend prior construct validity evidence to support the use of the FIQ‐SF by early childhood education programs such as Head Start serving diverse families from low‐income backgrounds. Implications for future research, practice, and policy applications in early childhood are discussed.