Born in the Basque Country to Ghanaian parents, Williams joined the club at the age of 20 from Basconia, progressing through the youth ranks to become a key figure in the first team.
Now 30 years old and serving as the vice-captain, Williams has clocked over 400 appearances for the club, setting a remarkable La Liga record with 251 consecutive matches.
His contributions have been vital, notably scoring the decisive goal in the 2020-21 Supercopa de Espana and playing a crucial role in securing Athletic's first Copa del Rey title in 40 years during the 2023/24 season.
"I would like to be a one-club man; spending my entire career at Athletic would be a source of pride for me," Williams shared in an interview with AS.
His journey is further enriched by the unique story behind his name, which was inspired by a Caritas volunteer who aided his family upon their arrival in Spain.
His younger brother, Nico, is also following in his footsteps as a forward, having developed through the same club's youth system.