Mr Ramaphosa, the nation’s deputy president, defeated former cabinet minister Nkosazana Dlamini-Zuma, Mr Zuma’s ex-wife, after a marathon voting process.
The 65-year-old is now in a strong position to become president after elections in 2019.
Mr Ramaphosa was a key ANC negotiator and strategist during South Africa’s transition to democracy.
The a vote has been decribed as the most pivotal moment for the party since it launched black-majority rule under Nelson Mandela 23 years ago.
Mr Ramaphosa is a former union boss who became a businessman and is now one of South Africa’s richest people.
The leadership battle caused fierce political infighting, raising fears the party may split before the polls.
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