Ramaphosa's African National Congress (ANC) won the poll but its share of the vote fell to a post-apartheid low, reflecting anger at corruption and cronyism under Ramaphosa's predecessor Jacob Zuma.

Many voters were also dismayed at the racial inequality that remains entrenched a generation since the former liberation movement took power.

Ramaphosa's election on Wednesday was greeted by clapping from a packed public gallery and opposition benches, including the far-left Economic Freedom Front, which had a fractious relationship with Zuma.

"I will be a president for all South Africans and not just a president for the African National Congress," Ramaphosa said.

"We have been given this responsibility on an overriding basis to revive our economy, to create jobs."

His influential deputy David Mabuza unexpectedly postponed taking up his seat to address accusations he had brought the ruling party into disrepute, owing to graft allegations.

Analysts said the move reflected Ramaphosa's strengthened authority to tackle reforms.

Ramaphosa, who is also the leader of the ANC, was elected without contest and will be officially inaugurated on Saturday.

Australian Associated Press