Gary Street, who led England's Women to 2014 World Cup victory, has left his role as head coach.
The Rugby Football Union said the decision was made by mutual consent.
Head of women's performance Nicky Ponsford will take charge of the team for the Six Nations along with Street's assistant coach Graham Smith.
"Since I got involved in the game, Gary's been the most prominent figure in women's rugby," said former England flanker Maggie Alphonsi.
It is understood the timing of Street's departure took many England players by surprise.
Smith will leave his post too, but not until the end of the Six Nations, which starts on 6 February and finishes in late March.
Street, who had been coach of the team since 2007, was in charge when England beat Canada 21-9 in August's Women's Rugby World Cup final in Paris to claim the title for the first time since 1994.
|BBC women's rugby commentator Sara Orchard|
|"Having tasted disappointment in the 2006 and 2010 finals, Gary Street's dogged determination and commitment led to his greatest legacy - leading England to World Cup glory in 2014. Along with Graham Smith the pair were more than just coaches to the players - friends and father figures to most.|
|"The timing of the announcement is the most curious thing, just two weeks out from England's opening Six Nations match away in Wales suggests a sub-plot as yet unknown.|
|"Both Street and Smith had made no suggestion of stepping down with both talking of hopes to retain the World Cup in 2017."|
"I am extremely proud of the part that I played in growing the women's game to where it is now," Street said. "The pinnacle has to be winning the Rugby World Cup in France last year.
"It is a moment I will cherish forever. I now feel that I have achieved everything that I set out to do, and this is the right time to explore new challenges in my career."
Alphonsi, who retired from England duty in September, said Street and Smith would both be sorely missed.
"To hear Graham's stepping down is going to be a huge loss, but no doubt both will go on to bigger and better challenges," she said.
"I don't know about what will happen in the future, but I do know they'll want to ensure that the women go on to win the next World Cup."
Street led England to five successive Six Nations crowns until 2012, before a difficult 2013 that saw his side suffer a comprehensive series loss to New Zealand, exit the Sevens World Cup at the quarter-finals and lose the Nations Cup Final to Canada.
Ponsford, a World Cup winner in 1994, said: "Many of those players who won in Paris last year have been developed and coached by Gary and Graham throughout their entire playing careers.
"However, we all felt the time was right to make some changes within the women's programme as we look to rebuild the team ahead of the next World Cup in 2017."