Background: Positive health behaviours (exercise, healthy diet, limiting alcohol and not smoking) can improve multiple outcomes after a cancer diagnosis. Observational studies during the pandemic suggested that health behaviours were negatively impacted for some but not all individuals living with and beyond cancer. The aim of this study was to qualitatively explore the impact of the pandemic on the health behaviours of people living with and beyond breast, colorectal and prostate cancer. Methods: Thirty participants were purposively sampled from participants in the ‘ASCOT’ trial for characteristics including: diagnostic group, gender, time since diagnosis and age. Semistructured interviews were conducted by telephone. Thematic analysis and a secondary Ideal Types analysis were conducted. Findings: Strict restrictions and changes in routines impacted engagement in positive health behaviours among many participants. Five themes covered modifications in: food, weight management, relationship to alcohol and exercise. Five “types” were identified, representing orientations to health behaviours. Discussion: Protracted amounts of time spent at home during the pandemic appeared to contribute to increased consumption of alcohol and unhealthy food, and reduced physical activity. Given the importance of healthy behaviours in this population, results from this study can help inform management of people living with and beyond cancer during future health emergencies. The typology helps to define how orientations to health behaviours underpin responses of people in this group. With further development, health behaviour interventions could be targeted based on individual orientations to health, rather than demographic or clinical variables.