West Ham have signed Finland international Oona Siren from LSK Kvinner on a two-year deal.
The midfielder made 19 top-flight appearances for the Norwegian club, providing four assists.
The 23-year-old becomes manager Rehanne Skinner’s eighth signing of the summer.
Siren has also played for Finnish top flight and in the Women’s Champions League qualifying rounds.
"I’m looking forward to the challenge of playing in England. I know the Women’s Super League is the best league in the world," said Siren.
"I want to test myself against the best players and the best teams. My experience of playing for Finland and in the Champions League has given me the motivation to keep pushing to be the best player that I can be.
"I know that coming to West Ham and working in this environment will help my development as a player. I can’t wait to get started."