Mr. Williams, 59, whose title is president and chief operating officer, joined the San Diego, Calif.-based chain in 1966 and climbed the company ranks, including a onetime post as executive vice president of marketing and operations, overseeing the famed "Jack's Back" campaign in 1995.
Mr. Williams, whose retirement is effective at the end of the year, will also resign his seat on the board. Chairman-CEO Robert J. Nugent, 60, will add the title president Jan. 1.
Meanwhile, effective July 8, Linda A. Lang, 44, will become executive vice president in charge of marketing, operations, human resources and information systems from senior vice president of marketing.
In addition, the company promoted three other officers effective July 8. They are Carlo Cetti, 58, to senior vice president of human resources and strategic planning; Karen Trissel, 35, to vice president of brand strategy and product development; and Terri Graham, 37, to vice president of brand communications and regional marketing.