The purpose of this design and development case study is to provide an in-depth account of the needs analysis (through surveys and interviews), design, development and formative evaluation of the Citizen Science Cancer Curriculum (CSCC). The curriculum was developed as an online, self-paced educational program distributed as an Open Educational Resource using Creative Commons licensing. The instructional approach described in this design and development case study was informed by the Self-Determination Theory (SDT) framework. The case reflects a new frontier in the development of community stakeholder engagement models and describes how evidence-based instructional design practices and approaches (e.g., storytelling) can be used to support Citizen Scientists' interests, learning and motivation to engage in cancer-related research. Results from quantitative and qualitative analyses indicate that the CSCC supported Citizen Scientists' learning performance and motivation. More specifically, the use of storytelling as an instructional approach supported Citizen Scientists' psychological needs, especially relatedness and competence, which translated into their behavioral intentions to contribute to cancer-related research. We share context-specific challenges and opportunities in working with Citizen Scientists as well as with cancer researchers and clinicians during the design and development of the curriculum.