Sienna Spiro, is a British singer-songwriter. Known for her distinct deep alto voice, she began sharing various viral singing videos on TikTok in 2022. She began putting out singles in 2024, including the UK No. 45 hit "Maybe". 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 reached No. 9 on the UK singles chart in November 2025.