Background and Aims: For older adolescents, the COVID-19 pandemic and associated UK restrictions arrived during a critical period in the transition to adulthood. Early research exploring impact of the pandemic paints a picture of worsened adolescent wellbeing and mental health. We explore the subjective experiences of 16- to 19-year-olds during the first UK lockdown, with an emphasis on wellbeing and coping, in order to complement emergent quantitative evidence and inform strategies and provision for support. Methods: In May 2020, we invited UK-based 16- to 19-year-olds to share their experiences of the initial lockdown for ‘[project name redacted for blinded peer review]’. 109 participants took part, submitting anonymous written accounts via an online portal. We used inductive reflexive thematic analysis to develop rich experiential themes.Findings: We constructed seven main themes: heightened emotionality; feelings of loss, change, and uncertainty; recognising the value of self-care; efforts to think positively; opportunities for relief, growth, and development; the importance of togetherness; and frustration with government and media. Implications: Findings highlight the multifaceted nature of adolescents’ lockdown experiences, and offer insight into emotional impact and new concerns as well as the value placed on self-care and staying connected. We offer directions for supporting adolescents as pandemic consequences continue.