Sienna Wareing signed for West Ham United women's team on 7 July 2026, as she penned the first professional contract of her career.

Wareing spent seven years at Manchester United and joined the Irons off the back of a successful 2025/26 campaign, having won the Red Devils' Academy U21 Player of the Year award and helped her former side lift the Professional Game Academy Plate.

Wareing’s footballing journey began at the age of seven when she played for her local boys’ side Mill Hill Juniors before moving to Blackburn Rovers for three years. She received her first England U19s call-up in April 2026 and made three appearances for the Young Lionesses in their 2026 UEFA Women’s U19 European Championship qualification campaign.