The business moves from DraftFCB in San Francisco. The media account remains with OMD.
The brief includes broadcast as well as in-room and promotional communications.
Creative work will be run out of Y&R in Chicago. The account team will be based at the Y&R office in Irvine, California, which has handled creative work for the Hilton brand since 2005.
Tom Sebok, the Y&R North America CEO, called the win "an exciting and important assignment for us".