Gabriel Da Silva converted a first-half penalty after Ricardo Steinmetz Alves was brought down in the box, while Martin Baron deflected the rattling ball into his own net in the second period to make sure of the win.
Five-a-side football, which is played by blind and visually-impaired footballers wearing eye masks, with sighted goalkeepers, made its debut in 2004 at the Athens Paralympics and the South Americans have not been beaten since.
At this year's competition at the Riverbank Stadium in east London, they did not concede a goal, while France had also come into the final with a clean sheet.
But the scoreline could have been different had veteran goalkeeper Fabio Ribeiro de Vasconcelos not saved two penalties, from David Labarre and Frederic Villeroux.
At the other end, Alves had two shots saved by French 'keeper Jonathan Grangier and another blocked, while Goncalves twice came close but shot wide.
Brazil coach Ramon Pereira de Souza said the win meant a lot to the team, as they came into the tournament under pressure to do well after their previous victories.
The two finalists had previously drawn 0-0 in the group phase but De Souza said his players had shown their class, pledging to follow up their success in Rio de Janeiro in 2016.
"Brazil are special, they are very united, the players they fit in very well together. In the beginning they were trying to get used to the pitch, the ground, it felt different for them and it took a while to get used to it," he said.
"After a while they were more aggressive and also tactically this time we played better... We hope to have the same success and also in the competitions before that."
In the bronze medal match, Spain and Argentina were goalless after regulation time but the Europeans went on to win 1-0 after penalties.