Deutsch LA pitched for the business against the San Francisco-based independent agency Eleven Inc. and the New York-based Taxi.
The appointment follows the announcement earlier in the year that creative duties on the Old Navy account, worth $180 million a year, would be decided on a seasonal basis. The New York office of the Dutch independent agency StrawberryFrog won the brand's back-to-school campaign in June.
PHD and Corinthian Media remain Old Navy's media agencies. Both media agencies are unaffected by the move to seasonal reviews.