The purpose of this study was to investigate the association between household economic changes by COVID-19 and dietary habits in Korean adolescents. The study analyzed data from the 17th Korea Youth Risk Behavior Survey in 2021. A total of 54,848 middle and high school students, 28,401 males and 26,447 females, participated in this study. COVID-19 lead to deterioration of household economy in the lower level of household economic status (p<0.001). The deterioration of household economic status by COVID-19 was associated with dietary habits such as lower breakfast intake, and higher fast food, soda drinks, and sweet drinks consumption (p<0.001). Logistic regression analysis showed that deterioration of household economic status was significantly decreased in frequency of breakfast intake (OR: 0.73, 95% CI: 0.67~0.80). The deterioration of household economic status by COVID-19 was also significantly associated with increased frequency of fast food (OR: 1.28, 95% CI: 1.16~1.41), soda drinks (OR: 1.42, 95% CI: 1.30~1.56) and sweet drinks (OR: 1.35, 95% CI: 1.24~1.46) consumption (p<0.001). In conclusion, it was confirmed that the change in household economy caused by COVID-19 was associated with dietary habits in adolescents. As the household economy deteriorated, there was an increase in undesirable dietary habits including skipping breakfast and fast food consumption.