Tom Malcolm, managing director of consumer marketing at Cohn & Wolfe, told PRWeek the agency's "integrated plans" would help raise awareness of Campari throughout the UK.
"The Negroni is the cocktail of the moment and we're looking forward to building on that platform by bringing to life the range of unique serves Campari has to offer," Malcolm said.
WPP-owned Cohn & Wolfe also works with wine-maker Treasury Wine Estates, and has worked with drinks brand Hennessy in the past. Campari is the only Gruppo Campari brand it is working with.
The account was previously held by W Communications through its work with Gruppo Campari, which owns a considerable number of drinks brands. These include Koko Kanu and Aperol, which W retains as clients.
Gruppo Campari recorded revenues of €1.6bn (£1.3bn) in 2015. Earlier this month, the group announced that it had acquired independent US dry gin brand Bulldog for $58.4m (£46.7m).