Nadine Riesen signed for West Ham United on 22 June 2026, following her departure from Frauen-Bundesliga side Eintracht Frankfurt.

Defender Riesen put pen to paper on a three-year contract at the Club and became Rita Guarino’s fourth signing of the summer transfer window after the arrivals of Katie Zelem, Constance Picaud and Laia Codina. A full-back who thrives in both halves of the pitch, Riesen joined the Hammers with experience in the UEFA Women’s Champions League, on the international stage and has played in Switzerland and Germany’s top flights.

Riesen has been playing first-team football since the age of 15, when she plied her trade with FC St. Gallen before spending two seasons at Swiss top-flight side BSC YB Frauen in Bern. The defender next enjoyed a fruitful two seasons at FC Zürich Frauen, alongside fellow Hammer Seraina Piubel, where she won back-to-back league titles in 2022 and 2023, as well as the Swiss Cup in 2022. With plenty of UEFA Women’s Champions League experience from her time in Switzerland, Riesen made the move to Germany to play for Frauen-Bundesliga side Eintracht Frankfurt in 2023, becoming a first-team regular from the 2024/25 season - making 69 appearances and contributing nine assists.

During her spell at Frankfurt, the defender had a summer to remember as Switzerland hosted UEFA Women’s Euro 2025. Riesen, who has won over 40 caps for her country since her senior debut in June 2019, featured in all four of Switzerland’s matches and scored in their opening group game against Norway.