Hopp, 49, was appointed vice chairman, chief operating officer and chairman of the agency's executive committee. He succeeds Peter Dow, 61, who will retire Feb. 1. Dow has been chief operating officer since 1982.
Hopp has spent his entire 26-year career with the company. Since 1977, he has had senior management responsibility for the agency's Chevrolet business, becoming executive vice president and account director in 1988. He was named president of the firm in 1993.
Hoag, 51, succeeds Hopp as president in addition to his current responsibilities as chief executive officer of sister company Lintas Marketing Communications.
Hoag joined Lintas Campbell-Ewald in 1968. In 1987, he became the founding president of Lintas Marketing Communications, which provides communications services for the agency's clients.