The agency, which pitched against Sid Lee and Anomaly, will create a strategic platform and campaign for the brand in new markets, including the UK.
Diageo has previously promoted Ketel One in the UK through branded events and sampling, partnerships with other premium brands and tutored tastings.
Grey New York will continue to manage the brand in the US. The agency picked up the global account in 2009 after a contest against M&C Saatchi, Wieden & Kennedy and Kirshenbaum Bond Senecal & Partners.
Ketel One is run by a joint venture between Diageo and the Dutch company Nolet Group. The vodka brand joined the Diageo family in February 2008.