For seriously ill hospitalized patients with a diagnosis of cancer, there exists a need for specialist palliative care, 24 hours a day, 7 days a week. This article describes the expansion of a palliative care consult service in a metropolitan, dedicated cancer hospital to provide 24/7 specialist palliative care including onsite overnight presence by advanced practice registered nurses and to evaluate the impact of this change on nighttime utilization of the consult service. Inpatient management encounters and outpatient calls were compared before and after the expansion. The onsite availability of a palliative care specialist between midnight and 8 AM increased from less than 10% of the time in 2019 to 100% of the time in 2021. The number of inpatient overnight calls and pages increased from a median of 4 to 16, and the number of follow-up visits evaluated increased from a median of 0 to 6. However, the number of overnight palliative care consults and outpatient calls evaluated did not change significantly. Expansion of a hospital-based palliative care service to include 24/7 onsite overnight presence increased patient, family, and night staff access to high-quality palliative care, prompt symptom management, and staff coaching on primary palliative care skills.