The risk of Type 2 Diabetes is 10 times higher after a pregnancy with Gestational Diabetes. Physical activity can independently reduce this risk, yet engagement with physical activity remains low after Gestational Diabetes. Therefore, the present study aimed to explore the barriers and facilitators to the uptake of physical activity after Gestational Diabetes in the United Kingdom, using a socio-ecological approach. The paper was written following the Standards for Reporting Qualitative Research. Patient and Public Involvement contributed to the study's conceptualisation and design. Participants were recruited through an audit of Gestational Diabetes cases at a local Teaching Hospital in 2020. Twelve participants took part in semi-structured one-to-one interviews. Reflexive thematic analysis was used to generate themes in iterative rounds of refinement. The final themes were then organised using the socio-ecological model. Participants were all over 31 years old, predominantly self-identified as White British and were all in employment but were evenly spread across UK-based deprivation deciles. Ten themes were generated and organised according to the four levels of the socio-ecological model: intrapersonal (beliefs about activity, recovering from birth), social (health care professionals, family and partner, role as a mother), organisational (access and cost, environment, childcare and work) and community (connecting women with recent Gestational Diabetes). Many of the amenable barriers and facilitators to physical activity were beyond the intrapersonal level, based on higher levels of the socio-ecological model (social, organisational and community). Multi-level interventions are needed to effectively address all barriers.