Chelsea have announced the signing of England midfielder Keira Walsh from Barcelona, with sources telling ESPN the deal is worth around €550,000 ($572,000).
The 27-year-old has signed a 4½-year deal with her new club.
Walsh was set to leave Barça at the end of the season on a free transfer if she did not sign a new deal, and the Spanish giants decided she should leave for a fee.
"It's unbelievable. I'm very happy to be here and very excited to get started," Walsh said in a statement.
"You look at the history of the trophies Chelsea have won and I'm an ambitious player and person, so for me, it is a good fit."
Walsh spent eight years at Manchester City where she won one WSL title and three FA Cups before joining Barcelona in 2022. She won eight trophies at the Catalan club, including two Champions Leagues and two Liga F titles.
The midfielder has made 80 appearances for England, winning Euro 2022 and losing the 2023 World Cup final to Spain.
Walsh becomes the latest major star in the women's game to move to the WSL, joining United States women's national team defender Naomi Girma at Chelsea.
"Keira is a player who will add huge value to an already talented squad," Chelsea's head of women's football Paul Green said. "She has vast experience at the highest level, winning major honours at both domestic and international level.
"She is a composed defensive midfielder, with excellent technical attributes and world-class football intelligence. Her playing style and ability to dictate the tempo of the game will be crucial to our game model as we move forward."
The WSL January transfer deadline closed on Thursday, with Arsenal completing a loan move for City's Chloe Kelly.
Chelsea, who are top of the WSL in manager Sonia Bompastor's first season in charge, face a trip to Aston Villa on Sunday.
Information from Reuters and ESPN's Tom Hamilton contributed to this report