Hospitalised children have become more medically complex and increasingly require specialised teams and units properly equipped to care for them. Within paediatric cardiology, this trend, which is well demonstrated by the expansion of cardiology-specific ICUs, has more recently led to the development of acute care cardiology units to deliver team-based and condition-focused inpatient care. These care teams are now led by paediatric cardiologists with particular investment in the acute care cardiology environment. Herein, we describe the foundation and development of an Acute Care Cardiology Advanced Training Fellowship to meet the clinical, scholarly, and leadership training needs of this emerging care environment.