Background: The impact of the novel coronavirus 2019 (COVID-19) on the health and well-being of adolescents with obesity is currently unknown. The shelter-in place (SIP) orders imposed disruptions in everyday routines for all persons, including youth with obesity. Obtaining real-time data could offer important information about how youth with severe obesity are faring in the midst of this global crisis. Hence, this cross-sectional study aims to assess the impact of the COVID-19 pandemic on health-related behavior changes in adolescent patients with severe obesity. Methods: Fifteen adolescents with severe obesity (M ± SD: 16.40 ± 1.67 years; 66.7% female; 40% Hispanic) and 19 parents (45.83 ± 6.98 years; 94.7% female; 47.4% Hispanic) receiving care at an adolescent bariatric surgery clinic at a university medical center participated (20% response). Participants completed an online survey about the impact of COVID-19 and SIP on: eating habits, physical activity, sleep, screen time, mood, and motivation for behavior change. Parents completed similar questions regarding the impact of SIP on their child’s health. Results: Descriptive analyses revealed adolescents reported varied sleep quality and quantity, later bedtimes, increased home-cooked and family meals, decreased takeout food consumption, and increased anxiety levels. Almost half reported increased snacking. Changes in physical activity were noted. Parent and adolescent responses were mostly aligned, with the exception of self-reported weight change. Conclusions: Adolescents with severe obesity are facing challenges in maintaining health-related behavioral goals during SIP. Providers should be prepared to discuss and manage the impact of COVID-19 on adolescent patients with obesity.