Source: Sharecast
Griffiths, who is only 51, was appointed FD in September 2008 and took on additional responsibilities and was appointed group chief operating officer in April last year when chief executive Adam Crozier stepped down, but was overlooked for the CEO role.
New CEO Carolyn McCall began in January this year after being poached from easyJet.
She said: "Ian leaves ITV in strong financial health. He has helped me steer the strategy refresh and will continue to be involved in embedding the implementation over the next few months. I and everyone at ITV will be sorry to see him leave and we wish him all the very best for the future."
Chairman Peter Bazalgette said Griffiths had helped develop and deliver the strategy that has created a strong platform the company's future and delivered value for shareholders.
Griffiths added: "ITV is a brilliant business with superb people and I have thoroughly enjoyed my time here. I am immensely proud of everything that we have achieved at ITV, not least in keeping the business together through the financial crisis and then delivering strong shareholder returns from 2010 onwards. I will be leaving a great team and a business in good shape. "