Billie ranks #331 with 359 entries and is one of the most generationally split female pet names on the chart. Older owners hear Billie Holiday; younger owners hear Billie Eilish. Both readings live comfortably under one name, and the result is unusually broad appeal.
The two-Billie lineage
Billie Holiday (1915-1959) gave the name a deep, classic register that survived in jazz-coded households for decades. Billie Eilish reintroduced the spelling to a Gen Z and millennial cohort starting around 2017, with a different valence — soft-grunge, alternative, and unmistakably current. Most pet adopters land on Billie via one of these two anchors, and the choice tells you a lot about the owner.
The gender-flexible factor
Billie reads as feminine in modern American naming despite its origins as a Bill diminutive. The -ie ending softens the masculine root, and pet owners almost universally use it for female pets. A small share of owners pick it gender-neutrally, but the female skew is strong on this one.
Sound fit and breed lean
Two syllables (BIL-ee), front-stressed, soft B and clean -ee finish. Recall is solid. The name pairs naturally with mid-sized friendly breeds, and Cocker Spaniels and friendly mixes wear it especially well. The human Billie page shows the name climbing on the SSA chart through the late 2010s and 2020s, riding both the Eilish wave and the broader -ie-ending revival alongside Frankie and Sadie.