The former Coventry and Burnley boss joined the Light Blues in July 2023 as assistant manager and helped Jo Potter’s side win both domestic cup competitions last season as well as qualifying for the Champions League.
Bradford will depart following Sunday’s match with Hibernian at Broadwood as the Women’s team head into the winter break.
Speaking exclusively to the Rangers website, she said: “This was not an easy decision for me as I have loved my time with the club.
“I had to weigh up several factors in both my professional and working life and at this time I felt it was the right move.
“It has been my pleasure to work with the group of players and I wish them, and the club - who I will continue to follow - every success in the future.”
Rangers Head Coach, Jo Potter, said: “I am disappointed to be losing Jay from the team.
“She was an integral part of my coaching staff and helped bring success to the club. However, I know in football that sometimes people need to move on and it can be for a number of reasons.
“I wish Jay every success in the future.”
Women’s and Girls Managing Director, Donald Gillies, commented: “Jay will be missed around the club.
“She has brought a period of success to Rangers both domestically and helped us to reach the European stage this term.
“We have started the process of finding Jay’s replacement and hope to update the supporters on this in the near future.”