Early diagnosis of cancer through screening can reduce deaths and treatment burden if the people invited participate. Yet inequalities in screening participation remain: ethnic minority groups in particular experience barriers to cancer screening that need to be addressed in order to contribute to improving equality in health outcomes. Community-centred, participatory approaches can ensure that cancer screening interventions are culturally appropriate to the communities they are intended to serve. Virtual participatory research faces unique challenges in building the rapport required for successful collaboration between participants and researchers. This article describes the successful adaption of face-to-face participatory methods to co-designing, online, an intervention using faith-based messages to reduce cancer screening barriers. Based on the World Café method, we conducted four two-hour workshops by video call with a group of 10 Muslim women (29–65 years) from Glasgow, UK. Activities included (i) plenary and small-group discussions, (ii) graphic recording, and (iii) expert presentations. The workshops covered four topics: Islam and health, screening barriers, faith-based messages for screening barriers, and delivering a faith-based intervention. Anonymous feedback questionnaires evaluating each workshop showed the women found the workshops interesting, informative, and helpful. They reported being glad they had participated. Our findings highlight the importance of interactive discussion and low participant burden to optimise online co-design. The workshops created a faith-based cancer screening intervention engaging and accessible to Muslim women.