This was after no people showed symptoms for two incubation periods since the last case.
The outbreak, the seventh in the former Zaire since the virus was identified there in 1976, was separate from the one spreading in West Africa, where more than 5,400 people have died.
There were 49 deaths out of 66 people infected in the remote north-western Equateur province during the three-month outbreak, Congolese authorities said last week. A WHO spokesman confirmed the figures.
(READ MORE: MSF sends specialists to DRC’s Ebola affected region)
Two maximum incubation periods of 21 days each must pass with no new cases being detected before the United Nations health agency can declare that an outbreak is finished.
“Having reached that 42-day mark, the Democratic Republic of Congo is now considered free of Ebola transmission,” the WHO said in a statement.
“WHO commends the Democratic Republic of Congo’s strong leadership and effective coordination of the response that included rapidly mobilising an expert response team to Jeera County, identifying and monitoring contacts and organising safe burials,” the WHO said.