CONTEXT: The need for children's palliative care (CPC) globally is unknown. To understand the scope of the need and to advocate to meet it, more accurate estimates are needed. OBJECTIVES: The objective of this study was to create an accurate global estimate of the worldwide need for CPC based on a representative sample of countries from all regions of the world and all World Bank income groups. METHODS: This work builds on previously published methods developed by the International Children's Palliative Care Network, United Nations Children's Fund, and World Health Organization and tested in three African countries. The study used a cross-sectional design with quantitative data obtained from primary and secondary data sources. Estimation of the need used prevalence data from the Institute for Health Metrics and Evaluation, mortality data from the World Health Organization for the specific diseases known to require CPC, and Joint United Nations Programme on HIV/AIDS (UNAIDS) data on HIV prevalence. Representative data were analyzed for 23 countries representing 59.5% of the world's population. RESULTS: The findings show estimated need for CPC ranged from almost 120 per 10,000 children in Zimbabwe to slightly more than 20 per 10,000 in the United Kingdom. Overall, among the over 21 million with conditions that will benefit annually from a palliative care approach, more than eight million need specialized CPC worldwide. CONCLUSION: The estimation of need for CPC is a critical step in meeting the needs of children with life-threatening conditions and provides a sound platform to advocate for closure of the unacceptably wide gaps in coverage.