France hosts approximately 368,000 'persons of concern' (e.g. refugees, stateless, people in refugee-like situations, asylum-seekers). Northern France has become a focal area, due to its proximity to the Dover entry-point to the UK and larger numbers of migrants. This study used a structural violence lens to explore the provision of health services to migrants in Calais and La Linière in northern France, to contribute to discourse on the effects of structural violence on non-state service providers and migrants in precarious conditions and inform service provision policies. Our qualitative study design used semi-structured key-informant interviews, conducted in summer 2017 with 20 non-governmental service-providers, 13 who had worked in Calais and 7 in La Linière migrant camp. We analysed interviews thematically, using inductive coding. Themes from analysis were: (i) power dynamics between NGOs and the state; (ii) resource allocation and barriers to accessing services; and (iii) effects of structural violence on social determinants of health. NGO service provision varied due to tense power dynamics between state and NGOs, shifting state requirements, and expanding roles. Interviewees described ongoing uncertainties, and inherent disempowerment associated with humanitarian aid, as negatively affecting migrant health and wellbeing, increasing illness risks, and providing unequal life chances. Structural realities including violence appeared to negatively affect migrant social determinants of health, reducing healthcare access, social inclusion, and sense of empowerment. The role of NGOs in providing migrant health services in northern France was complex and contested. Structural violence negatively affected migrant wellbeing through restricted services, intentional chaos, and related disempowerment. The violence exerted on migrants appeared to diminish their life chances while being an ineffective deterrent, indicating better approaches are needed.