Metropolitan Police Commissioner, Dame Cressida Dick is leaving her role after series of damaging controversies.
Dame Cressida said she had been left with “no choice” after London Mayor Sadiq Khan made it clear to her he had no confidence in her leadership.
Last week, the police watchdog found “disgraceful” misogyny, discrimination and sex harassment among some Met PCs.
Dame Cressida, the first woman to lead the biggest UK police force, also faced criticism over the Sarah Everard case.
Ms Everard was murdered by a serving Met Police officer, Wayne Couzens, in March last year.
Speaking on BBC London hours before her departure was announced, she insisted that she had “absolutely no intention” of quitting, and that she was “seething angry” about the culture at Charing Cross police station, which was exposed by the police watchdog.
In her resignation statement, Dame Cressida said she had “agreed to stay for a short period to ensure the stability of the Met”.
Mr Khan said he was “not satisfied” with Dame Cressida’s response to the scale of change required to “root out” racism, sexism, homophobia, bullying and misogyny in the Met.
“On being informed of this, Dame Cressida Dick has said she will be standing aside,” he said.
Mr Khan thanked the commissioner for her 40-year policing career.
He said he would now “work closely with the home secretary on the appointment of a new commissioner” with an aim to restore trust in the force.
Prime Minister Boris Johnson said Dame Cressida “has served her country with great dedication and distinction over many decades”.
Home Secretary Priti Patel said the police chief held the role “during challenging times” and that she “exemplified the increasingly diverse nature of our police”.