Arsenal Ladies manager Laura Harvey will leave in January to take over at American side Seattle Reign.
Harvey, 32, joined the club as first-team coach in 2008 and replaced Tony Gervaise as manager in February 2010.
"I've had a wonderful four-and-a-half years and would like to thank everyone at the club for the fantastic support," she told the club's website.
"A special thanks must go to (general manager) Vic Akers for giving me the opportunity to manage this special club.
"It was always going to be a huge challenge taking over from such a legendary figure in the women's game but I've learnt so much from Vic and can't thank him enough for all that he's done for me."