The unemployment rate hit 32.9% between January and March, up by 0.8 of a percentage point on the previous quarter, national statistics agency StatsSA said.
"The number of unemployed persons increased by 330,000 to 8.2 million," it said.
High unemployment is a key political issue ahead of national and provincial elections on May 29.
Young people in particular lament the lack of prospects in what is usually regarded as Africa's most industrialized economy.
Youth unemployment was 45.5% in the first quarter, up 1.3 percentage points on the previous three months.
In power since the advent of democracy in 1994, the ruling African National Congress (ANC) has been experiencing a sharp decline in support.
Beset by graft and mismanagement allegations amid a slumbering economy, it is expected to drop below 50% of the vote for the first time in the general election on May 29.
If the party falls short of a parliamentary majority, it would be forced to seek coalition partners to remain in power.
The high unemployment rate has fueled protests as well as anti-foreigner sentiment.
The liberal Democratic Alliance (DA), the leading opposition party, jumped on the figures to attack the ANC and highlight that unemployment was lower in DA-run provinces.
"The jobs bloodbath that continues everywhere that the ANC governs, is a most compelling reason to vote the ANC out in two weeks' time," said its shadow labour minister, Michael Bagraim.