This study is designed to assess the socioeconomic effects of COVID-19 pandemic on small and medium scale business enterprises' sustainability, with focus on Nigerian youths. Three research questions were raised and a null hypothesis was formulated to guide the study. The survey inferential research design was adopted, the study population are the Nigerian youths engaged in small and medium scale business enterprises across the 36 states of Nigeria. Using the multistage random sampling and accidental/purposeful techniques, a sample of 6000 respondents were selected for the study. The researchers designed structured questionnaire divided into three sections to cover the three questions raised was used for data collection. The administration of the instrument was done within eight weeks. Data was analyzed using simple percentage and Pearson Product Moment Correlation Analysis to test the null hypothesis. The result shows that 25 small and medium scale business enterprises were categorized and used for the study, out of the 6000 respondents used for the study, 3791 respondents (63.2%) were males, while 2209 (36.8%) were female entrepreneurs. The result further identified 14 ways the COVID-19 pandemic affected the socioeconomic activities of small and medium scale business enterprises among the youths. The result of the correlation analysis yielded a calculated r-value of 0.688 and a table value of 0.176 at 0.05 significance level and a degree of freedom of 5998, indicating that COVID-19 pandemic has significant effects on SMEs' sustainability in Nigeria. Based on this, it was concluded that the COVID-19 pandemic has caused very severe significant effects on small and medium scale business enterprises, the major players in this sector are the youths, hence COVID-19 pandemic has dealt a devastating effect on SMEs. It is therefore recommended among others that there should be the strict observation of all preventive -control protocols as prescribed by the agencies concerned in Nigeria and world over. It was further recommended that government and other agencies can make palliative capitals as soft loans for those whose businesses were badly affected to start all over again or continue from where they stopped.