Chelsea have completed the signing of USA defender Naomi Girma for a world record fee for a female player.

The 24-year-old has signed a contract until summer 2029 after the Women’s Super League (WSL) leaders this week agreed to pay San Diego Wave about £900,000.

“I’m so happy and really excited to be here. It doesn’t feel real,” Girma told the Chelsea website before being introduced to fans at Stamford Bridge for Sunday’s WSL match against Arsenal.

“There are a lot of things about Chelsea that made me want to come here – the culture, the winning mentality, staff and players.

“It’s a top environment to learn and grow in. Right now, that’s what I’m looking to do. It was an easy choice for me.”

The fee exceeds the previous record of £685,000, when Bay FC signed Racheal Kundananji last February.

Chelsea set the British transfer record in signing Mayra Ramirez for £384,000 in January 2024.

Girma is Chelsea’s first signing of the January transfer window after they fought off competition from Lyon.

Chelsea made her a priority target after losing defender Kadeisha Buchanan to a season-ending knee injury.

Head of women’s football Paul Green said: “Naomi is a world-class defender who is now coming into the prime years of her career.

“Her composure on the ball, ability to read the game, coupled with her pace and athleticism, will add top quality to an already very talented squad.

“She is undoubtedly ready for this next step in her career and we are delighted it will be with Chelsea.”

In 2023 Girma helped San Diego win the National Women’s Soccer League (NWSL) Shield and was named US Soccer’s female player of the year.

She was part of the USA side that won gold at the 2024 Olympics in Paris.

Emma Sanders, BBC Sport women’s senior football reporter

Girma’s talents are no secret and she is widely regarded as one of the best female footballers.

Former Chelsea boss Emma Hayes, now the USA manager, said last year Girma was the world’s best centre-back and she will no doubt be pleased to see her old club scoop her up.

Having enjoyed a taste of silverware with the USA and San Diego, Girma arrives in England with ambitions to win more trophies, particularly in the Champions League, and is believed to have had discussions with Hayes about what to expect from Chelsea.

Lyon offered higher wages and were prepared to match the transfer fee that Chelsea eventually had accepted by San Diego, but Girma’s preference was always to join the Blues.

It is manager Sonia Bompastor’s most significant signing to date and the club believe Girma will take them one step closer to a first European title.

The long-term deal agreed is also a statement of intent from Chelsea – that they are able to attract the world’s best talents and, hopefully, keep them.