The Met boss will lave the top job on Sunday, April 10, following a troubled period for the London force.
Dame Cressida tweeted confirming the news on Saturday morning in a tweet.
She wrote: “My last working day as Met Commissioner will be 10th April. It has been a tremendous honour to serve the people of London and the UK. "I will share more on the work of my brave officers and staff next week.”
Deputy Commissioner Sir Steve House will serve as acting commissioner while the recruitment process is ongoing to find Dame Cressida’s successor, according to the office of Mayor of London Sadiq Khan.
Dame Cressida resigned her role under pressure earlier this year, in the wake of a series of scandals that led to widespread criticism of the culture within the ranks.
It came after a series of scandals for the Met, and public outrage over its handling of incidents including a vigil for Sarah Everard, who was kidnapped, raped and murdered by serving officer Wayne Couzens.
Shortly before she resigned, an Independent Office of Police Conduct probe darkened the growing cloud over the force, when it uncovered homophobia, misogyny, racism and sexism among a group of officers at Charing Cross police station.
At the time of her announcement she was stepping down, Dame Cressida revealed the mayor had told her he "no longer has sufficient confidence in my leadership to continue."
This morning, the mayor's office said Mr Khan will work closely with Home Secretary Priti Patel to appoint a new commissioner “to address the deep cultural issues facing the Met Police Service”.
A spokesperson for Mr Khan said: “The mayor thanks Dame Cressida Dick for her decades of public service.
“The mayor has been clear that candidates for the next commissioner must have a plan to restore the trust and confidence of Londoners.”