"A full day in Durban awaits tomorrow as PM @narendramodi arrives in this old port city of South Africa," External Affairs Ministry spokesperson Vikas Swarup tweeted.
Durban is home to 800,000 of the around 1.2 million people of Indian origin in South Africa, making it the city with the largest Indian population outside of India.
On Saturday, Modi will undertake a train journey to Pietermaritzburg station in memory of the 1893 incident in which Mahatma Gandhi was thrown out of a train compartment on account of his skin colour.
Following this, he will visit Gandhi's Phoenix Settlement.
He will also attend a meeting of the Alumni Network and a reception in his honour to be hosted by the Mayor of Durban and the Indian High Commissioner to South Africa before leaving for Tanzania on Saturday evening on the third leg of his four-nation African tour.
India and South Africa signed four agreements on Friday following delegation level talks headed by Modi and South African President Jacob Zuma in Pretoria.
He also addressed a Indian diaspora rally in Johannesburg prior to his departure for Durban.
Modi arrived in South Africa from Mozambique on Thursday night on the second leg of his African sojourn.
This is his first visit to mainland Africa and is also the first prime ministerial visit from India to South Africa since then Prime Minister Manmohan Singh arrived in 2013 for the G20 summit in Durban.
Apart from Mozambique, South Africa and Tanzania, Modi will also visit Kenya.