From 8 November, the airline will increase its Heathrow-Johannesburg service from three-times-weekly to daily.
Virgin is also bringing forward the resumption of its Heathrow-Cape Town service, with three-times-weekly flights now due to get under way from 17 December.
Juha Jarvinen, Virgin Atlantic chief commercial officer, said: “We know there’s pent-up customer demand for travel to South Africa so I’m thrilled we can offer our customers more services to both Johannesburg and Cape Town."
Jarvinen added: “We’re expecting a high proportion of leisure travellers on these routes, taking advantage of the winter sun, the safaris and the world-famous wine region."
Flights to Johannesburg and Cape Town will be operated by Virgin’s Boeing 787-9 aircraft with 31 Upper seats, 35 Premium and 192 Economy.
Johannesburg fares lead in from £478pp return and Cape Town from £578pp return.