Objective. Social media (SM) has gained almost ubiquitous use in society and especially among adolescents; however, there has been rising concern over its negative consequences, including the effects on child behavioral health, such as sleep and internalizing symptoms. Research elucidating the impacts of SM use on young people should be conducted to inform healthier SM usage. This study seeks to understand how SM use and use of phones around bedtime associates with worse sleep quality, depression, and anxiety among youth during the peak of the COVID-19 pandemic and social distancing. Methods. This project uses archival data collected in fall 2020 through school-based surveys to adolescents in a rural school district in Michigan. There were a total of 200 participants (91.7% response rate) of which 180 adolescents (12-15 years old, 40.0% male, 55.6% female, 3.9% nonbinary) were included in the analysis based on their SM use, the majority of whom identified as white (91.7%). Results. Linear regression analyses indicated that higher self-reported SM use was associated with poorer sleep quality and greater depression ( p < 0.05 ). Sleep quality mediated the association between SM use and depression ( p < 0.05 ). Furthermore, youth who brought their smartphones to bed with them had poorer sleep quality than those without phones ( p < 0.05 ). SM use was not associated with anxiety after controlling for age and gender. Conclusions. SM use is associated with higher rates of adolescent depression; however, sleep appears to mediate the relationship. The impacts of bringing a smartphone to bed and self-reported SM use on adolescent mental health may be better predicted via sleep disruption even during a widescale event such as COVID-19.