"We are going to South Africa - it's not a question of if, it's only when," Ecclestone said in comments due to be published in South African newspapers today.
"There will be a South African Grand Prix hosted by Cape Town within five years," he said.
But when asked to be more specific he added "Three years, tops".
"It will be good for Formula One, for South Africa and the city. Plans are well advanced and I believe that the government may well become involved," he said.
A South African consortium announced plans last August to join the Formula One circuit in 2007 but wanted government backing for a bid it said could boost the country's economy by more than a billion rand ($162.2 million) a year.
"We have just concluded a constructive round of talks with Formula One Management and have formed the South African (F1) Grand Prix Bid Company which will formally apply for the licence in the early part of next year," consortium chief executive Dave Gant said in a statement released on Tuesday.
"We are currently in continued talks with government in respect of their participation and these are proving extremely positive.
"We already have a commitment from the private sector for 50 per cent of the funds that we require from that source.
"Renowned F1 track designer, Hermann Tilke, will be visiting the proposed site in December and will begin the process of design of the track and infrastructure," Gant said.
Since apartheid white rule ended 10 years ago, South Africa has raced to make up for decades of sporting isolation, hosting a string of international events including the cricket and rugby World Cups.
