Objectives: The study aimed to analyze the effects of household financial difficulties caused by COVID-19 (2019 coronavirus disease) on suicidal tendencies of adolescents. Methods: We selected 54,948 middle and high school students who were surveyed based on the Korean Youth Risk Behavior Web-based Survey 2020. To analyze the data, we used the STATA 16.0 program to conduct propensity score matching (PSM). Results: After controlling for selection effects by using PSM, the household financial difficulties caused by COVID-19 maintained a significant predictive effect on increasing suicidal ideation, suicide attempts, and decreasing tendency in hospital-treated after suicide attempts. However, depressive symptoms and suicide plan did not show a significant correlation with household financial difficulties associated with COVID-19. Conclusions: It was found that the rate of suicidal ideation and suicide attempts among adolescents who experienced a household financial difficulties due to COVID-19. Therefore, It can provide empirical evidence for estimating the impact of COVID-19 on adolescent suicide rates.