The UK's direct aid to South Africa will end in 2015, International Development Secretary Justine Greening will announce.
The Government's aid programme to South Africa is currently worth £19 million a year, down from its peak of more than £40 million in 2003, and has focused on reducing the mortality rate among women giving birth, as well as supporting businesses.
The Government will continue to fund its current projects but speaking at conference of African ministers and business leaders in London on Tuesday, Ms Greening will say that bilateral aid to South Africa, which has been in place for more than 20 years, should come to an end.
The UK's relationship with South Africa should now be based on trade and not development, Ms Greening will say.
In her speech, she will tell the conference: "South Africa has made enormous progress over the past two decades, to the extent that it is now the region's economic powerhouse and Britain's biggest trading partner in Africa.
"We are proud of the work the UK has done in partnership with the South African government, helping the country's transition from apartheid to a flourishing, growing democracy.
"I have agreed with my South African counterparts that South Africa is now in a position to fund its own development.
"It is right that our relationship changes to one of mutual co-operation and trade, one that is focused on delivering benefits for the people of Britain and South Africa as well as for Africa as a whole."