The 26-year-old has put pen to paper on a one-year deal, and becomes the fourth women’s team signing of the window, following the arrivals of Danique Kerkdijk, Matilde Skovsen and Megan Walsh.
Hope Powell said, “It is a pleasure to welcome Lea to the club, and she is someone with plenty of experience of playing at the very highest level in France, and for the national team too.
“Lea will add to the healthy competition for places in the midfield positions, and I am very much looking forward to working with her.”
Le Garrec began her senior career at Evreux, before subsequent moves to Montigny-le-Bretonneux and Paris St Germain.
She joined Guingamp for her first spell at the club in 2012, and was there for two years before a move to Saint Malo in 2014. Le Garrec returned back to Guingamp in 2016, ahead of her latest move to the Albion.
The midfielder has represented France from every level from under-16s to the seniors, and was part of the under-19 squad that won the European Championships in 2010.