Sony chief executive Sir Howard Stringer will step down from the job at the beginning of April.
He will be replaced vice president Kazuo Hirai, who has been expected to take over since being made head of consumer products and services in March.
Sir Howard will stay on as chairman of the Japanese electronics company.
Sony is predicting a fourth year of losses for the year to the end of March, blaming a strong yen and poor sales in its television business.