Delirium is a common medical complication in people living with cancer, particularly with more advanced disease. Delirium is associated with significant symptom burden which causes distress and impacts quality of life. As recommended by international guidelines, a high degree of suspicion is needed to ensure delirium is detected early. Attention to collateral history can provide clues to changes in cognition and attention. Non-pharmacological approaches that can be considered essential elements of care are effective in reducing the risk of delirium. Delirium screening using a validated measure is recommended as even expert clinicians can underdiagnose or miss delirium. The diagnostic assessment requires consideration of the cancer diagnosis and comorbidities, in the context of potential reversibility, goals of care, and patient preferences. The gold standard approach based on expert consensus is to institute management for delirium precipitants supported by non-pharmacological essential care, with the support of an interdisciplinary team. Medication management should be used sparingly and for a limited period of time wherever possible for severe perceptual disturbance or agitation which has not improved with non-pharmacological approaches. Clinicians should be familiar with the registered indication for medications and seek informed consent for off-label use. All interventions put in place to manage delirium need to consider net clinical benefit, including harms such as sedation and loss of capacity for meaningful interaction. Clear communication and explanation are needed regularly, with the person with delirium as far as possible and with surrogate decision makers. Delirium can herald a poor prognosis and this needs to be considered and be discussed as appropriate in shared decision-making. Recall after delirium has resolved is common, and opportunity to talk about this experience and the related distress should be offered during the period after recovery.