Objective Resident-to-resident aggression (RRA) in nursing homes is a matter of serious and profound concern, yet action to eliminate or mitigate RRA is hampered by a paucity of research. The aim of this study was to explore key stakeholders’ knowledge and perceptions of RRA in Australian nursing homes. Methods A qualitative cross-sectional study design was used, and semistructured telephone interviews were conducted. Participants were purposively and conveniently sampled with replacement from a range of aged care, healthcare and legal professional bodies, as well as advocacy organisations. The interview contained 12 closed-ended questions and six open-ended questions about participants’ knowledge, experiences, perceptions and attitudes to RRA. Participant characteristics and responses to closed-ended questions were aggregated and proportions calculated, and thematic analysis was conducted by two independent researchers using a directed content approach. Results Fifteen participants (11 females; 73.3%) in senior management positions were interviewed. All were familiar with the concept of RRA and just over half (n=8; 53.3%) had witnessed an incident. Major themes included the nature and causes of RRA and attitudes and responses to RRA. Potential causes of RRA included maladaptation to nursing home life, transfer of pre-existing issues into the nursing home environment, physical environment and staffing-related issues. RRA was commonly viewed by participants as dangerous and unpredictable or, conversely, as expected behaviour in a nursing home setting. A person-centred care approach was considered most effective for managing and responding to RRA. Conclusion The research demonstrates that understanding perceptions of RRA among key stakeholders is critical to identifying the nature and scope of the problem and to developing and implementing appropriate prevention strategies. What is known about the topic? RRA is common in nursing homes, with potentially fatal consequences for residents involved, and has serious implications for nursing home staff, managers, providers, and regulators. Despite this, the prevalence, impact, and prevention of RRA remains under-recognised and under-researched in Australia. What does this paper add? This is the first Australian study to produce qualitative findings on the knowledge and perceptions of RRA in nursing homes among key stakeholders. This paper reports on the knowledge and perceptions of individuals in senior management and policy roles in aged care and related fields in relation to four themes: nature; causes; attitudes; and responses to RRA. Our findings highlight the complex and multifactorial nature of RRA. What are the implications for practitioners? A movement towards person-centred care that promotes understanding of individual care needs is favoured as an approach to reducing RRA. Increased reporting of both minor and major incidents of RRA will help to identify patterns and inform appropriate responses. However, a cultural shift is first required to recognise RRA as a manageable and preventable health care and adult safeguarding issue.