PURPOSE: This longitudinal study investigated distress rates in patients with advanced ovarian cancer during the COVID-19 pandemic and examined whether time, illness representations, and coping strategies predicted distress levels. METHODS: UK patients with stage 3 or 4 ovarian cancer were recruited between September 2020 and March 2021. Data were collected at baseline (T0), 2 months (T1), and 4 months (T2) post-enrolment. Validated questionnaires assessed distress (anxiety, depression, PTSD, fear of progression) and predictors (coping strategies and illness perceptions), analysed via multilevel modelling. RESULTS: Seventy-two participants returned a questionnaire at T0, decreasing to 49 by T2. High distress was observed, with over 50% of participants experiencing anxiety and depression consistently. Nearly 60% reported clinical levels of fear of progression at some point. PTSD rates resembled the general population. Although distress levels remained stable over time, some individual variability was observed. Time had minimal effect on distress. Coping strategies and illness perceptions remained stable. Threatening illness perceptions consistently predicted distress, while specific coping strategies such as active coping, acceptance, self-blame, and humour predicted various aspects of distress. Together, these factors explained up to half of the distress variance. CONCLUSION: The findings have implications for routine screening for distress and the inclusion of psychological treatment pathways in advanced ovarian cancer care. Addressing illness representations is crucial, with attention to informational support. Future research should explore the long-term effects of heightened distress and the effectiveness of interventions targeting illness perceptions. This study informs current clinical practice and future pandemic preparedness in cancer care.