Cyril Ramaphosa has become South Africa's president a day after embattled leader Jacob Zuma resigned.
He was the only candidate nominated by parliament, which is dominated by his African National Congress. MPs broke into song at the announcement.
In his first presidential speech, Mr Ramaphosa, 65, said he would tackle the corruption which allegedly became widespread under Mr Zuma.
The ANC had told Mr Zuma to step down or face a vote of no-confidence.
President Ramaphosa told parliament that corruption and state capture were "on our radar screen".
He is due to deliver a State of the Nation address on Friday. This was delayed last week amid uncertainty about who should deliver it and Mr Zuma's reluctance to step down.
One opposition party, the Economic Freedom Fighters, walked out of the parliamentary debate. It wants new elections, rather than the ANC deciding on the identity of the new president.
