Sienna Ann Spiro (born 28 September 2005) is an English singer-songwriter and record producer. Known for her distinct and powerful voice, she began sharing viral singing videos on TikTok in 2021. She started releasing music in 2024, including "Maybe", which became her debut on the UK Singles Chart. She released Sink Now, Swim Later, her debut extended play, in February 2025. Her breakthrough success came with the release of "Die on This Hill", which charted in numerous countries. She released her debut studio album, Visitor, on 3 July 2026.