The country is top of a shortlist of African nations where they are expected to create a home from as early as next year, The Sun can reveal.
Another Commonwealth state, Botswana, is a close second.
The recommendations have been made in a top-secret briefing document about how the couple will establish their future after the imminent birth of their first child.
But sources close to the Duchess of Sussex last night rubbished speculation that Meghan wanted to move back to the US and one day become the American president, insisting she had no political ambitions.
We have learned senior members of the Royal Family, including the Queen and Prince Charles, have come on board with the African plan.
But there are concerns within the royal household about the costs of the move. There would be a huge security bill for eight full-time police staff to relocate permanently with Meghan and Harry, who has visited South Africa on numerous occasions.
Officials there and in Botswana have not yet been consulted because the discussions are at an early stage.
A royal source said: “Harry and Meghan are very much engaged in these plans, although the move isn’t planned until next year or 2021.
“The idea is they will spend between three and four months every year based in an African country, where they would work and then use it as a base for travel.
“South Africa and Botswana are two countries on the shortlist that are considered the most likely.”
Sources close to Harry, 34, and Meghan, 37, insisted the exact scope of the role they would play in Africa had not yet been determined.
The insider explained: “A briefing paper has been prepared and shared with a very small circle.
“They’re starting to look at how the next couple of years of their lives are going to be spent and looking at some long-term strategic planning. It’s all a part of a process.
“They have a vision of being ambassadors for the UK, representatives of the Commonwealth and pursuing the works and good causes they want to focus on.
“They like the idea of being able to put roots down in a country, have a home base and really get involved and engaged in the community and country. Africa is an obvious starting point for Harry because of his affinity for the continent.
“But how it is all worked out from the official side is still to be developed because these are such early-stage conversations and we are not there yet.”
Concerns within the royal household have already been expressed about who will foot the bill, with at least the security costs expected to be picked up by the government.
The source said: “Taxpayers will likely have to fund this role to the tune of many millions of pounds a year.
“They will require a massive security detail, with at least eight officers based with them permanently. It would be much more expensive than their security bill in the UK.
“But the argument will be that the costs are worth it because this will be a good thing for Brand Britain, which we need at the moment.”
Prince William is believed to be supportive of the plans now that he and Kate have split their household from the Sussexes, who are based at Buckingham Palace.