Nicholas "Nico" Williams Arthuer (born 12 July 2002) is a Spanish professional footballer who plays as a winger for Athletic Bilbao B. Williams joined the youth academy of Athletic Bilbao in 2013. He began his senior career with Althletic's reserve side Basconia for the 2019–20 season. Williams was promoted to the Athletic Bilbao B side on 11 May 2020. He made his professional debut with the senior Athletic Bilbao side in a 2–2 La Liga tie with Real Valladolid on 28 April 2021. Williams first represented Spain with the Spain U18s in 2020, scoring two goals in four games. He was called up to the Spain U19s in February 2021. Williams was born in Pamplona, Spain to Ghanaian parents who were refugees in Liberia. Nico's older brother, Iñaki Williams, is also a footballer and a forward; he too was brought up at Athletic Bilbao.