Many children with disabilities (CWD) engage in less physical activity (PA) than their typically developing peers. Messaging campaigns that target parents of CWD can promote PA participation amongst CWD. Guided by the Adapted Social Issue Advertising Believability Model, the aim of this study was to inform the development of PA promotion messages targeted at parents of CWD. Focus groups were conducted with parents of CWD (N=28; Mage=49.23; 57.14% female) to examine factors related to message uptake including parents' attitudes, perceived behavioural control regarding support for their children's participation in PA, and their messaging needs regarding preferred methods and messengers of message content. Preliminary findings of a qualitative content analysis revealed that participants valued the use of reputable brands, accreditation, and narrative stories to enhance message believability. Participants highlighted attitudinal beliefs (e.g., parent enjoyinment in supporting their child) and control beliefs (e.g., confidence to provide support, programming and resource awareness) that may be suitable to target in messaging campaigns. Participants also highlighted the need for child belongingness and engagement, two elements of quality PA participation. Messaging campaigns that illustrate PA as an opportunity for belonging and engagement may be particularly persuasive. Sponsored messages that highlight available resources, use narrative stores, and promote belongingness and engagement, may be effective in motivating parents to support PA participation among CWD.