BACKGROUND: General practice is a highly sedentary occupation, with many GPs spending more than 10.5 hours sitting each workday. This excessive sedentary behaviour and lack of physical activity (PA) is potentially detrimental to the health of GPs, as well as their ability to counsel patients regarding sedentary behaviour and PA. There is a lack of prior research examining the perspectives of GPs regarding their sedentary behaviour and PA. AIM: To explore GPs' perspectives regarding their sedentary behaviour and PA. DESIGN & SETTING: A qualitative interview study of GPs in Northern Ireland. METHOD: Semi-structured interviews were conducted with a purposive sample of 13 GPs who had previously taken part in a study to objectively measure their levels of sedentary behaviour and PA. Interview transcripts were analysed using deductive thematic analysis. The Theoretical Domains Framework (TDF) was used to facilitate identification of barriers and enablers affecting the ability of GPs to increase their PA. RESULTS: Key themes were categorised within six theoretical domains (environmental context and resources, social professional role and identity, goals, social influences, knowledge, and intentions) with sub-themes within each domain. CONCLUSION: Most GPs are unhappy with their current levels of sedentary behaviour and PA, and are concerned with how this is affecting their health. Numerous barriers and facilitators were identified affecting the ability of GPs to increase their PA, including working environment, and personal and professional responsibilities, among others. Addressing these could improve the health of GPs and their ability to counsel patients regarding sedentary behaviour and PA.