Introduction. Restrictions, social isolation measures, increased stress, and changing daily routines during the COVID-19 pandemic led to a significant decrease in young adults’ physical activity levels and sleep quality. Objective. The aim of this study is to examine the relationship between the physical activity levels and sleep quality of young people studying at a university during the COVID-19 pandemic. Method. This descriptive, correlational study was conducted with 670 young adults studying healthcare. Data was collected using the International Physical Activity Questionnaire-Short Form (IPAQ-SF) and Pittsburgh Sleep Quality Index (PSQI) and student information form. Results. 73.1% of the students reported insufficient sleep and 12.7% reported no physical activity. It was determined that 92.5% of the students whose average IPAQ-SF score was 2107.64 ± 54.70 MET-min/week and total PSQI score average was 7.51±2.92, increased their internet use and 94% used smartphones. A moderate negative relationship was found between the overall mean PSQI score and sleep duration, and between habitual sleep efficiency and the overall mean PSQI score. Discussion and Conclusion. The COVID-19 pandemic negatively affected students’ physical activity and sleep quality, highlighting the need for targeted interventions to improve this situation.