Billy is a distinctive girls' name in United States, ranking #7554 in 2025 with 14 recorded births. The name reached its all-time peak in 2022 with 16 births ranking #7031. In 2025, approximately 1 in every 114,805 girls born was named Billy. RISING Recent data shows the name is currently rising.
Billy is the familiar short form of William and carries the inherited meaning usually given as "resolute protector". It feels open, friendly, and much less formal than the full traditional version.
Billy has long been used as both a nickname and a stand-alone given name. It remains especially familiar in Britain and the United States through its mix of informality and tradition.