We are facing an unprecedented time during the COVID-19 pandemic. Measures have been taken to reduce the spread of the virus, including school closures and widespread lockdowns. Physical isolation combined with economic instability, fear of infection, and uncertainty for the future has had a profound impact on global mental health. For adolescents, the effects of this stress may be heightened due to important developmental characteristics. Canadian adolescents (n = 1,054; Mage = 16.68, SD = 0.78) completed online surveys and responded to questions on stress surrounding the COVID-19 crisis, feelings of loneliness and depression, as well as time spent with family, virtually with friends, doing schoolwork, using social media, and engaging in physical activity. Results showed that adolescents are very concerned about the COVID-19 crisis and are particularly worried about schooling and peer relationships. COVID-19 stress was related to more loneliness and more depression, especially for adolescents who spend more time on social media. Beyond COVID-19 stress, more time connecting to friends virtually during the pandemic was related to greater depression, but family time and schoolwork was related to less depression. For adolescents with depressive symptoms, it may be important to monitor the supportiveness of online relationships. Results show promising avenues to stave off loneliness, as time with family, time connecting to friends, as well as physical activity were related to lower loneliness, beyond COVID-19 stress. These results shed light on the implications of the COVID-19 pandemic for adolescents and document possible pathways to ameliorate negative effects. (PsycInfo Database Record (c) 2020 APA, all rights reserved)