The COVID-19 pandemic has affected household food security, especially those with low incomes. This study aims to: (1) analyze the influence of socio-demographic factors (gender, age, mother’s education, marital status, occupation, dependents, income, and social assistance) on food security. (2) Measuring the level of food security of low-income families in the Special Region of Yogyakarta seen from the share of food expenditure, using a cross-sectional design and a quantitative approach and involved a sample of 250 low-income households, determined randomly by purposive sampling technique. We collected data through questionnaires, and the data were analyzed using descriptive statistical methods and multiple linear regression models using SPSS software. Three socio-demographic variables affect food security: employment, income, and the number of dependents. Simultaneously, these factors significantly affect the respondents’ food consumption expenditure. This study found that only 42.4% of respondents had food security. It shows that the current COVID-19 pandemic has exacerbated the poverty experienced by respondents. As for recommendations: (1) The government needs to provide social protection to help low-income households through food assistance programs. (2) Social protection programs need to be combined with household-based socio-economic empowerment programs to improve the food security of low-income households sustainably.