South Africa edged greatest rivals New Zealand 12-11 to achieve a record fourth title in a gripping final last Saturday in Paris.
With gold medals hanging from their necks, the players arrived at the Union Buildings, the seat of the government, on a yellow open-top bus and shook hands with Ramaphosa.
"Saturday night, you strode off the pitch of victory and passed into legend," said Ramaphosa, who this week declared a public holiday on December 15 to celebrate the win.
"In doing so you have lifted the spirits of an entire nation and filled us with pride. You have united the South African people."
Thousands of people lined the streets to greet a team that has captured the hearts of a nation but was once reviled as a symbol of apartheid.
"We are very diverse, just like you are outside there and we just wanted to show that diversity is our strength," said Siya Kolisi, the Springboks' first black Test captain, dedicating the trophy to "the people of South Africa".
For 90 years Springbok selectors chose only white players, with black and mixed-race athletes sequestered in separate leagues.
That slowly started to change after the advent of democracy in 1994, with Nelson Mandela famously rallying behind the team that won its first World Cup in 1995.
The latest success brought joy to a nation still described by the World Bank as the most unequal in the world and battling unemployment, electricity, water and crime crises.
"The performance of the Springboks... has reminded us that even amidst our many challenges, there is always room for optimism and hope," said Ramaphosa.
Later Thursday, the Springboks will visit Johannesburg and its township of Soweto. They will go to Cape Town on Friday, Durban on Saturday and East London on Sunday.
