Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or COVID-19 pandemic affected many international students, including the Sri Lankan youth and young adults who were studying in the United Kingdom (UK), and repatriated to the motherland during the first wave. The current study aimed to explore and understand the lived experiences, behaviour, and psychological patterns of these students during their lockdown in the UK; quarantine and self-isolation; and repatriation back to Sri Lanka. Methods: This descriptive qualitative study was planned and conducted in a quarantine environment based on the lived experiences of two authors (KA and NW), who were also repatriated students due to COVID-19 pandemic. A convenient sample of sixteen (16) repatriated students (age ranged from 18 – 34) participated in the study. Data was collected using multiple methods including questionnaires, researchers’ objective observations and semi-structured interviews (conducted over the phone or online). The thematic analysis method was used for data analysis. Results: Both positive and negative psychological and behavioural patterns were observed. Three themes emerged were: (1) Fear, worry and anxiety, (2) Irritability and agitation, and (3) Adherence to safety precautions. Many reported negative abrupt changes to their education and lifestyles during this stressful situation. Perceived stigma and emotional imbalance have caused difficulty in coping. Positive changes such as increased efficacy in academic activities, exploring new hobbies and healthy coping skills were also reported. Conclusion: Findings highlight the need for addressing age-specific behavioural, psychological, and educational needs of youth and young adults when developing guidelines to manage similar situations in the future and to increase resilience.