ObjectiveThis study set out to investigate the risk of household food insecurity in Nigeria during the novel COVID-19 pandemic using a harmonised dataset of Nigeria’s prepandemic face-to-face survey and two waves of the COVID-19 National Longitudinal Phone Survey (NLPS).SettingNigeria.ParticipantsA representative sample of 1674 households is used in the analysis.DesignA longitudinal study.ResultsOur longitudinal study reveals a significant increase in the prevalence of food insecurity in Nigeria during the COVID-19 crisis. For a sample of 1674 households used in the analysis, nearly 32% were moderately food insecure in the baseline survey (ie, the prepandemic period), compared with 74% and 72% that faced the same degree of food insecurity in the two waves of the COVID-19 phone survey. In like manner, not up to 4% of the households faced severe food insecurity in the prepandemic period, compared with 43% and 22% that experienced the same level of food insecurity during the period of the pandemic. Based on the available information in the dataset, we construct a composite non-monetary measure (or index) of household well-being and employ the binary logistic model to investigate the objects under study. The empirical results show that the well-being index has a strong negative association with household food insecurity. Further investigation reveals that the risk of being food insecure increases for households in relatively poor living conditions compared with those in the middle category and conversely declines for households in much better living conditions.ConclusionThis study informs an understanding of the prevalence and risk of household food insecurity in Nigeria during the novel COVID-19 pandemic and provides insights that can guide policy actions in responding to the current wave of food crises in Nigeria.