The Omnicom-owned agency's sister agency PHD has also scooped media planning and buying for the hotel group.
BBDO succeeds Havas' Euro RSCG in New York, which parted company with Hyatt in the spring after just nine months on the business.
The agency won through in a pitch process that also included The Martin Agency in Richmond, Virginia; Bartle Bogle Hegarty in New York; Cutwater in San Francisco and Publicis & Hal Riney in San Francisco.
The review is focused on the Hyatt master brand and does not include the sub-brands Hyatt Place and Hyatt Summerfield Suites, which Cramer Krasselt in Chicago continues to handle.