Objective: During the COVID-19 pandemic, the prevalence of depression and anxiety among children and adolescents significantly increased, along with the number of visits to emergency departments due to suicidality and/or suicide attempts. Relatedly, health care workers experienced significant burnout and symptoms of anxiety, depression, and posttraumatic stress disorder during this time. However, the corresponding impact on psychiatric inpatient treatment has not yet been researched. We hypothesized that during the pandemic, adolescents hospitalized in an acute care psychiatric inpatient unit had increased incidents of suicide attempts and nonsuicidal self-injurious behaviors and of aggressive behaviors toward others, resulting in greater use of constant observation and restraints. Method: This study was a retrospective chart review based on electronic medical record data examining use of restraints and constant observation one year before the pandemic (March 2019 to February 2020) and 1 year following the onset of the pandemic (March 2020 to February 2021) in an acute-care adolescent (12 to 17 years old) psychiatric inpatient unit. Results: There were 571 admissions during the year before the pandemic and 500 admissions during the pandemic. The number of patients who were restrained (χ2 = 7.86, p = 0.005), number of patients who were placed on constant observation (χ2 = 13.41, p < 0.001), and number of constant observation orders per patient (χ2 = 91.90, p < 0.001) were all significantly greater during the pandemic. Conclusion: Psychiatrically hospitalized adolescents during the pandemic received more intensive interventions such as restraints and constant observation. Severe patient psychopathology and staff shortages, as well as limitations of and decreases to the dialectical behavior therapy program, may have been the contributing factor.