Cyril Ramaphosa was elected President of South Africa by parliament on Thursday after Jacob Zuma resigned overnight, heeding orders of the ruling African National Congress to bring an end to his nine scandal-plagued years in power.

Ramaphosa said he would work hard "not to disappoint the people of South Africa" in brief remarks after he was elected.

"The issues that you have raised, issues that have to do with corruption, issues of how we can straighten out our state-owned enterprises and how we deal with state capture are issues that are on our radar screen," the 65-year-old said.

South Africa's main stock market index jumped nearly 4 percent, putting it on track for its biggest one-day gain in more than two years as investors welcomed Zuma's resignation after nine years in office plagued by corruption allegations.

The rand, which has gained ground whenever Zuma hit political turbulence, soared to a near three-year high against the dollar on word of his resignation.

But the road back to prosperity and self-respect under Ramaphosa, who became ANC head in December, will be long and hard in a nation still polarised by race and inequality more than two decades after the end of white-minority rule.

Still, Zuma's departure late on Wednesday provided evidence of the strength of South Africa's democratic institutions, from the courts to the media and the constitution.