Ramaphosa was elected unopposed in the National Assembly this afternoon. The announcement was welcomed by singing in the National Assembly.
The 65-year-old leader was elected as the new President of the African National Congress (ANC) two months ago.
Zuma, 75, last night stepped down after he was ordered by the ANC's national leadership to quit or face a no confidence emotion in Parliament.
The ANC has a large majority in parliament.