Leah Galton will leave Manchester United after eight years with the club when her contract expires this summer.
The 31-year-old joined United as a member of their first professional squad in 2018.
Along with Ella Toone and Millie Turner, she is one of three remaining 'originals' from that group in United's current squad.
Galton made 171 appearances for the club and her 44 goals make her United's second-highest scorer of all time, behind Toone's 64.
"I never thought I would be here for this long and still doing the thing I love doing, so I'm always proud of how far I've come," Galton said.
United boss Marc Skinner added: "Leah has played an important part in the journey of this club. Being part of the club from the very beginning and contributing over so many years is something that's meant a lot to us.
"She's been involved in many significant moments along the way and has helped us grow into the club we are today."
Galton has struggled with a back injury this season and has made just four Women's Super League appearances, but the clubs said she is "in training and hopes to play some part in our conclusion to the season".
