Gypsies, Roma and Travellers (GRT) are socially excluded groups where evidence for improving health is weakest. Although GRT communities are diverse, and robust evidence of health needs is lacking, there is consensus that GRT in the UK have poorer health and lower life expectancy than the general population and other disadvantaged groups. Reasons why GRT are vulnerable to poor health outcomes include poor living conditions, high rates of homelessness, low educational achievement, social exclusion, widespread prejudice and discrimination and barriers to accessing healthcare. These multiple factors, alongside poor quality care that does not meet needs, may lead to low expectations and mistrust of health services. Trust in services and personnel is associated with increased utilisation of healthcare, improved health behaviours and quality of care. Community engagement strategies have the potential to enhance trust and ensure services are tailored to the needs of specific populations. This multi-component study aimed to strengthen evidence on how to improve uptake and delivery of health services and thereby reduce health inequalities for GRT.