Sienna Spiro is 20 years old as of 2026.

Quick Scoop: How old is Sienna Spiro?

  • Multiple music and fan sites list her birthdate as late September 2005.
  • These same sources describe her as 20 years old in 2026.
  • She is a London-born British singer‑songwriter who first gained attention on TikTok before releasing official singles and her debut EP.

So if you’re searching “how old is Sienna Spiro,” the latest publicly available info points to her being 20 years old right now.

Information gathered from public forums or data available on the internet and portrayed here.