lenpol7
It is 'Brasilia'. It is a purpose built capital city , some one thousand miles inland from Rio de Janeiro. It was constructed in the 1950's.
Neither Rio de Janeiro nor Sao Paulo are the capital city.
?
The federal capital city of [the Federative Republic of] Brazil is Brasilia, which is located in the Federal District.
Murzy
Brasilia .
az_lender
Brasilia. But why ask "us" when it's so easy to Google...