Billy

Billy is an unexpectedly feminine usage of what is traditionally a masculine nickname for William. When used for girls, Billy typically represents a diminutive of feminine names like Wilhelmina, Billie Jean, or simply Billie. This gender-crossing usage became somewhat fashionable in the mid-20th century alongside other masculine-leaning nicknames for girls. The feminine use of Billy peaked in the 1930s-1950s in the United States, influenced by figures like Billie Holiday, though the spelling 'Billie' was always more common for females. The name conveys a tomboyish, vintage charm with its friendly, approachable sound. In contemporary usage, female Billys are quite rare, with parents more likely to choose the explicitly feminine spelling 'Billie' to differentiate from the masculine form.

Pronounced BIL-ee.

As of October 2026, Billy ranked #7554 in US births in 2025 SSA, peaked at #526 in 1930.