Objective: : Chronic Fatigue Syndrome, a condition characterised by extreme fatigue that is not explained by other medical conditions, places individuals at greater risk of COVID-19. The condition is also associated with a lack of social support and social isolation. These individuals may, therefore, have a unique experience of lockdown and the pandemic. The present study investigates the experiences of those with Chronic Fatigue Syndrome during the COVID-19 pandemic. Design: : In the present study, we identified fifty online forum (Reddit) posts, discussing the personal lived experience of Chronic Fatigue Syndrome during lockdown and the global pandemic. These posts were subject to inductive thematic analysis. Results: : Four themes were extracted from the data. These were (i) Symptom Change, (ii) Social Interactions, (iii) Comparing Experiences, and (iv) Positive Consequences. Themes highlighted both positive and negative experiences of the COVID-19 pandemic. For example, whilst some people reported more severe symptoms, lockdown also provided more accessible opportunities to interact (i.e. online videocalls). Conclusion: : Chronic Fatigue Syndrome influenced physical, psychological, and social experiences, with both positive and negative outcomes of the lockdown and pandemic apparent. Findings have the potential to support those with Chronic Fatigue Syndrome and those who experience post-COVID-19 fatigue.