Abstract Introduction It is increasingly recognised that for the foreseeable future most hospital inpatient contacts with older adults will be completed by doctors not specifically trained in geriatric medicine. To guarantee the delivery of sufficient healthcare, it is essential that every hospital doctor is equipped with geriatric medicine competencies. Which exact competencies are required and how they should be prioritised for hospital doctors serving the older adult population remains unclear. Allowing for the broad, complex and multidisciplinary nature of geriatric medicine, we carried out a group concept mapping (GCM) study to determine the geriatric medicine competencies required by all hospital doctors. Methods GCM is a mixed methods approach utilising six phases to generate expert group consensus, enabling participants to organise and represent their ideas in order to identify a common understanding about competencies required by all hospital doctors. Healthcare professionals, patient advocacy groups and clinical educators generated and sorted ideas and then rated identified competencies. Hierarchical cluster analysis and multi-dimensional scaling were utilised to analyse participant input. Results Thirty-four stakeholders generated 88 competencies. Twenty completed the subsequent sorting and rating of competencies. Nine competency domains were identified by participants as integral for all hospital doctors to care for older adults: communication skills, medicolegal affairs, prescribing, delirium, falls and bone health, engaging specialist services, universal principles of care, managing hospitalisation and components of specialist gerontology. Domains rated most important related to interpersonal communication skills, medicolegal concerns, recognition, and management of delirium. Conclusion The nine competency domains indicate the diverse skillset required by all doctors to provide comprehensive care to older adults within a hospital setting. This study identifies competencies that may serve as a foundational framework for ensuring quality healthcare for the ageing population. Future initiatives should consider incorporating these competencies to improve inpatient care provided by hospital doctors to older adults.