Palliative care (PC) aims to improve quality of life (QOL) for patients with serious illness and their families by recognizing and alleviating the physical, emotional, social, existential, and spiritual suffering of patients and their communities. Because adolescents and young adults (AYAs, age 15-39 years) with cancer commonly report distress across all these domains and because that distress translates to their QOL during and after their cancers, PC is particularly relevant for this population. Here, we review the evidence for PC among AYAs with cancer, including its rationale, gaps, opportunities, and implications for care delivery. For example, nearly 90% of AYAs with cancer report distressing symptoms during their treatment, those who survive report ongoing unmet psychosocial and physical health needs, and those who die from their cancers are highly likely to receive medically intense care that is discordant with their goals and values. AYA communication and decision making can be challenging because of ethical and developmental considerations regarding the patient's autonomy and competing priorities of patients and caregivers. PC interventions (including primary PC delivered by oncologists, routine PC subspecialty care, symptom tracking, advance care planning, and psychosocial programs promoting AYA resilience) are all associated with improved patient-centered outcomes. However, PC is inconsistently integrated into AYA oncology care, and access to PC programs is not equitable; marginalized groups continue to experience poorer outcomes. Ongoing and future research and clinical initiatives must continue to bridge these gaps. Improving the QOL of AYAs with cancer is a shared goal of the larger clinical oncology community, and including PC in AYA cancer care delivery can help attain that goal.