Adolescent mental health has been under-researched, particularly in Africa. COVID-19related household economic stress and school closures will likely have adverse effects. We investigate the relationship among adolescent mental health, adult income loss, and household dynamics during the pandemic in Kenya. Methods: A cross-sectional mobile phone-based survey was conducted with one adult and adolescent (age 10e19 years) pair from a sample of households identified through previous cohort studies in three urban Kenyan counties (Nairobi, Kilifi, Kisumu). Survey questions covered education, physical and mental health, and COVID-19-related impacts on job loss, food insecurity, and healthcare seeking. Logistic regression models were fit to explore relationships among adult income loss, household dynamics, food insecurity, and adult and adolescent depressive symptoms (defined as PHQ-2 score 2). Results: A total of 2,224 adulteadolescent pairs (Nairobi, n ¼ 814; Kilifi, n ¼ 914; Kisumu, n ¼ 496) completed the survey. Over a third (36%) of adolescents reported depressive symptoms, highest among older (15e19 years) boys. Adult loss of income was associated with skipping meals, depressive symptoms, household tensions/violence, and forgoing healthcare. Adolescents had 2.5 higher odds of depressive symptoms if COVID-19 was causing them to skip meals (odds ratio 2.5, 95% confidence interval 2.0e3.1), if their adult head of household reported depressive symptoms (odds ratio 2.6, 95% confidence interval 2.1e3.2). Conclusions: Income loss during the pandemic adversely affects food insecurity, household dynamics, healthcare-seeking behavior, and worsening adolescent depressive symptoms. With schools reopening, adolescent mental health should be formally addressed, potentially through cash transfers, school or community-based psychosocial programming.