The company also said former U.S. Trade Representative Carla Hills is stepping down from the board in accordance with retirement policies.
Turner, the brash cable television magnate who founded Cable News Network in 1980, gave no reason for his decision in a brief statement distributed by Time Warner.
"It is after much deliberation that I have decided not to stand for reelection at the annual meeting," he said. "I have enjoyed working with Dick Parsons as well as the other board members and the management team."
Parsons, the Time Warner chief executive who just ended a long and public battle with billionaire Carl Icahn over how to boost the value of the world's largest media company, described Turner as a "visionary leader" in a brief statement.
Parsons said Turner had "made an extraordinary contribution to this company and, indeed, to the world at large."
Both Turner and Hills will continue to serve as directors until the company's board meeting.
Turner, whose first fame came as a sports baron and yachtsman, was chairman of Turner Broadcasting System Inc., when Time Warner Inc. acquired it in 1996 for $7.5 billion, creating the world's largest communications company.
While he has served as vice chairman of Time Warner, Turner has complained at times that he has been shunted aside by the media giant, and he has been critical of some of its past high-ranking executives, including former CEO Gerald Levin and AOL founder Steve Case.