Introduction The COVID-19 pandemic had an unprecedented impact on global food security, but little is known about the impact on food security at the household level. We examined the prevalence and socioeconomic demographic factors for household food insecurity during the COVID-19 pandemic in Papua New Guinea. Methods Household socioeconomic demographic data from the Comprehensive Health and Epidemiological Surveillance System were collected from six main provinces in 2020 (37880 participants) and compared with the 2018 data (5749 participants). The prevalence of household food insecurity was estimated and stratified by household socioeconomic demographic characteristics. Multinomial logistic regression was conducted to estimate adjusted OR (aOR) and 95% CI of risk factors. Results The overall prevalence of household food insecurity increased from 11% in 2018 to 20% in 2020, but varied across provinces, with the highest level reported in Central Province (35%) and the lowest level in East New Britain Province (5%). Food shortages were 72% less likely among urban residents than those living in rural areas (aOR 0.28 (95% CI 0.21 to 0.36)). The risk of food insecurity was 53% higher among adults aged 25+ years with primary education (grades 3-8) than those with university education (aOR 1.53 (95% CI 1.09 to 2.13)). People from households in the poorest wealth quintiles were 80% more likely to report food shortage than those from the richest wealth quintile (aOR 1.78 (95% CI 1.29 to 2.45). Conclusion The study provides evidence to develop policy and intervention to deal with food insecurity in emergency situations in the future.