Bernard Valcourt, the minister of the Atlantic Canada Opportunities Agency, says the money is aimed at increasing awareness of the region among travellers from the United States and United Kingdom.
Valcourt says the funding will focus on marketing and advertising, with an emphasis on social media.
The federal government will provide about $10 million, the provinces $6.6 million and tourism industry associations will offer the rest.
The initiative is a renewal of a three-year tourism partnership that the federal government says generated about $280 million in tourism revenue in the Atlantic provinces as of 2009.
Another such agreement expires later this year.