The agency triumphed after pitching last week against Media Planning Group, MindShare, Vizeum and Universal McCann.
Brand Connection, the incumbent on the account, which has now been merged into its sister Interpublic agency Initiative, did not repitch for the business.
Waitrose reviewed its media arrangements after its six-year deal with Brand Connection came to an end.
Brand Connection's merger with Initiative, which handled the Tesco media account, was also thought to have sparked the pitch.
Christian Cull, the marketing director at Waitrose, said: "Manning Gottlieb OMD showed a good understanding of the needs of the business, a strong appreciation of the marketing strategy and the agency put together a very good team."
Separately, Waitrose's parent, the John Lewis Group, is holding a review of its £13m creative account, which is held by Burkitt DDB. The agency also handles media for John Lewis and the store group will kick off a media pitch if the agency loses the creative business.
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