"The funds complement contributions by all the local United Nations agencies," in response to an urgent June appeal by the government, the UN said in a statement.
The money will partly be used to help train health agents and for a public awareness campaign via the media.
Some 1,900 cases of cholera have been registered over the last two months, a medical official said, with the capital city hardest hit by the epidemic.
Cholera is a waterborne disease which causes serious diarrhoea and vomiting and can be fatal if not treated within 24 hours.
Strong rains have "facilitated the rapid spread of the disease," said Agostinho Pedro Semedo, director of Bissau's central hospital.