The group, home to shows such as Britain's Got Talent, Broadchurch and Coronation Street, said Mr Crozier would leave on 30 June with a long-term successor to be revealed "in due course".
Sky News revealed in December that ITV had laid the groundwork for his departure by hiring corporate headhunters to oversee succession planning.
Chairman Sir Peter Bazalgette said he had "made a fantastic contribution to ITV".
Since then its share price has surged by 270% as he guided the business away from a heavy reliance on the turbulent advertising market.
He has steered it towards more involvement in making and selling hit shows to other broadcasters, buying independent producers in Britain and overseas.
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ITV said revenues from sources other than advertising had more than doubled to almost £1.9bn under Mr Crozier's tenure, to represent more than half the total.
Mr Crozier said he now planned to "build a portfolio of roles" elsewhere in business.
He added: "Today ITV is more robust, well-balanced and stronger both creatively and financially than ever before, and is well placed for the digital future."