Over the past five decades, palliative care has evolved from serving patients at the end of life into a highly specialized discipline focused on delivering supportive care to patients with life-limiting illnesses throughout the disease trajectory. A growing body of evidence is now available to inform the key domains in the practice of palliative care, including symptom management, psychosocial care, communication, decision-making, and end-of-life care. Findings from multiple studies indicate that integrating palliative care early in the disease trajectory can result in improvements in quality of life, symptom control, patient and caregiver satisfaction, quality of end-of-life care, survival, and costs of care. In this narrative Review, we discuss various strategies to integrate oncology and palliative care by optimizing clinical infrastructures, processes, education, and research. The goal of integration is to maximize patient access to palliative care and, ultimately, to improve patient outcomes. We provide a conceptual model for the integration of supportive and/or palliative care with primary and oncological care. We end by discussing how health-care systems and institutions need to tailor integration based on their resources, size, and the level of primary palliative care available.