Background: The COVID-19 pandemic has amplified concerns about global food insecurity, with dietary diversity emerging as a critical indicator of nutritional adequacy. These challenges have far-reaching implications for mental health, particularly in vulnerable populations.

Objective: This study delves into the intersection of post-COVID-19 household food insecurity, dietary diversity, and mental depression among affected households.

Methodology: A cross-sectional study conducted with a sample size of COVID 19 affected 500 households. Bivariate linear regression performed to establish associations with food insecurity, dietary diversity, and depression.

Result: The study found that only 33.4 % of households were food secure, while 40.8 % experienced moderate food insecurity. Most households (82.2 %) had a medium level of dietary diversity, and 45.6 % of respondents reported experiencing different level of depression. Urban residency, higher education, stable employment, and higher income were associated with lower food insecurity and better dietary diversity ((p < 0.05), whereas female-headed households, joint families, and older family heads had higher levels of depression. Job losses (63 %) and income reductions (69.8 %) during COVID-19 contributed significantly (p < 0.05) to increased food insecurity and depression. Households with stable jobs, higher incomes, and access to nutritional information enjoyed better food security, greater dietary diversity, and lower depression. In contrast, rising food prices and job changes worsened both food insecurity and mental health outcomes.

Conclusion: The COVID-19 pandemic has impacted food security, dietary diversity and mental health in Jashore, Bangladesh, exacerbating food insecurity and mental depression, especially among vulnerable groups. However, households with stable jobs, better education, and access to information fared better.