Background: The COVID-19 pandemic coincides with growing concern regarding the mental health of young people. Older adolescents have faced a particular set of pandemic-related challenges and demonstrate heightened vulnerability to affective disorders (particularly anxiety). Anxiety symptoms are associated with a range of cognitive difficulties. As such, older adolescents may be susceptible to pandemic-related declines in both wellbeing and cognitive function.Methods: At three timepoints, independent samples of young people aged 16-18 years (N = 607, 242, 618 respectively) completed an online survey. Data collection coincided with periods of lockdown (timepoints 1 and 3) and young people returning to school (timepoint 2). The survey assessed subjective impacts of the pandemic on overall wellbeing, anxiety and cognitive function.Results: Findings demonstrated the detrimental impact of the COVID-19 pandemic on older adolescents’ psychological wellbeing. Crucially, heightened anxiety was associated with self-identified cognitive difficulties, and this pattern of association was sustained in subsequent independent samples. Furthermore, the nature and extent of these difficulties were predictive of particular pandemic-related concerns in this age group.Conclusions: Older adolescents’ experiences of the pandemic are characterised by a clear pattern of association between anxiety and self-identified cognitive difficulties, which was sustained over time. Implications are discussed with reference to both future research and intervention. Abbreviations: Exploratory Factor Analysis (EFA); Confirmatory Factor Analysis (CFA)