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Sia

Photo: (Kirk Stauffer), CC BY-SA 3.0, via Wikimedia Commons

Singer

Sia

Australian singer and songwriter (born 1975)

Sia is 50 years old, born on December 18, 1975 in Adelaide.

Next birthday in 45 days, turning 51.

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Born
December 18, 1975, Adelaide
Age
50
Zodiac sign
Sagittarius
Country
Australia
Known as
Singer

Official links: Official website (siamusic.net) · Instagram · X · YouTube · TikTok · Wikipedia

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Sia’s birthday, by the numbers

  • Sia was born on a Thursday.
  • Sia has been alive for about 18,583 days.
  • Their 20,000-day milestone falls on September 20, 2030.
  • Their next birthday, turning 51, is on a Friday.
  • Next milestone: Sia turns 60 on December 18, 2035, in 9 years and 1 month. More milestone birthdays
  • Sia is younger than 3,186 and older than 3,660 of the living celebrities on CFOTD.
  • Half birthday: June 18. Birthstone: Turquoise, tanzanite and zircon.
  • Sia belongs to Gen X.

Age gaps

Born within weeks of Sia

Milla JovovichActor · December 17, 1975Sushmita SenActor · November 19, 1975Mayim BialikActor · December 12, 1975Emma BuntonSinger · January 21, 1976DJ KhaledMusician · November 26, 1975Rick RossRapper · January 28, 1976

Days and weekdays are worked out from the birth date. Compare Sia’s age with anyone.

Share Sia’s birthday, December 18?Make something for yourself or a birthday friend.
🏅Birthday certificateAdd a name, download a PDF or image🎂Printable birthday pageA free one-page PDF for December 18⭐Birthday twin cardA square card to share

Also born on December 18

All →
Christina AguileraSinger · Age 45Steven SpielbergFilm director · Age 79Brad PittActor · Age 62Keith RichardsMusician · Age 82Ashley BensonActor · Age 36Katie HolmesActor · Age 47

Also born in 1975

All →
David BeckhamSoccer player · May 2Enrique IglesiasSinger · May 8Charlize TheronActor · August 7Bradley CooperActor · January 5Kate WinsletActor · October 5Milla JovovichActor · December 17

Birthday wishes from fans

Send Sia a birthday wish, or tell other fans why you love their work. The first good one goes right here.

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Birth dates and details from Wikidata (checked October 15, 2026, newest names added October 27, 2026). Ages update every day. Photos are freely licensed and credited on each profile. How we build this site · Report a mistake

Frequently asked questions

How old is Sia?

Sia is 50 years old, born on December 18, 1975 in Adelaide.

What is Sia’s zodiac sign?

Sagittarius, born December 18.

Does Sia have an official website?

Yes: siamusic.net.