How Old Is Billie Eilish — Billie Eilish was born December 18, 2001, which makes her 24 years old as of mid-June 2026. She turns 25 on her next birthday in December 2026.

Biography.com and People list Billie Eilish's birth date as December 18, 2001, in Los Angeles. That Sagittarius birthday anchors every age calculation fans search for online.

To answer how old is Billie Eilish, subtract 2001 from the current year and adjust if today is before December 18. Mid-2026 means age 24 until that birthday passes.

From bedroom-studio demos to Grammy-sweeping debut albums, Billie Eilish's age tracks a meteoric career. Each release era arrives at a new chapter in her sound and public image.

Billie Eilish will turn 25 on December 18, 2026 — the same date fans mark every year with birthday posts and streaming parties. Until then, verified sources list her as 24 years old.