The international liver glycogen storage disease (GSD) priority setting partnership (IGSDPSP) was established to identify the top research priorities in this area. The multiphase methodology followed the principles of the James Lind Alliance (JLA) guidebook. An international scoping survey in seven languages was distributed to patients, carers, and healthcare professionals to gather uncertainties, which were consolidated into summary questions. The existing literature was reviewed to ensure that the summary questions had not yet been answered. A second survey asked responders to prioritize these summary questions. A final shortlist of 22 questions was discussed during an international multi‐stakeholder workshop, and a consensus was reached on the top 11 priorities using an adapted nominal group technique.In the first survey, a total of 1388 questions were identified from 763 responders from 58 countries. These original uncertainties were refined into 72 summary questions for a second prioritization survey. In total 562 responders from 58 countries answered the second survey. From the second survey, the top 10 for patients, carers and healthcare professionals was identified and this shortlist of 22 questions was taken to the final workshop. During the final workshop, participants identified the worldwide top 11 research priorities for liver GSD. In addition, a top three research priorities per liver GSD subtype was identified.This unique priority setting partnership is the first international, multilingual priority setting partnership focusing on ultra‐rare diseases. This process provides a valuable resource for researchers and funding agencies to foster interdisciplinary and transnational research projects with a clear benefit for patients.