In a super-sized version of the crowds that packed "Jurassic Park" outside the team's arena to watch game telecasts, supporters lined the streets to witness players ride by on open-topped buses.
"You think the parade is going to be amazing and you can't even picture this," Raptors coach Nick Nurse said. "It's pretty cool."
People began camping out overnight to fill Nathan Phillips Square to it's 65,000-person capacity, police told people not to come to the stage area because it was so jam-packed, subway stations were closed to limit access.
The Raptors beat defending champion Golden State 114-110 on Thursday in California to capture the best-of-seven NBA Finals four games to two, setting the scene for the screaming and cheering celebration.
"It's amazing," Raptors star Kawhi Leonard said. "Everybody is out. I don't think anybody went to work today. Everybody got the day off. Look at it. It's crazy.
"Thank you Canada for the support. We did it."
Leonard, who could opt out to become a free agent, said the team has been celebrating ever since they ran off the court in Oakland.
"The last few days have been amazing," Leonard said. "No sleep. A lot of celebrating. And we're going to keep going."
Players wore T-shirts, sunglasses and held cigars and champagne as they watched people line Lake Shore Boulevard and York Street.
"This is why we wanted to win a championship," Raptors guard Kyle Lowry said. "This is unbelievable. And we ain't even close to being done."
The last time Toronto celebrated a major North American sports title was in 1993 when the Toronto Blue Jays won baseball's World Series.
Canada, a country of 37 million, had 20 million people watching the telecast of game six.
- 'Joy on people's faces' -
The parade slowed through the concrete canyons, well behind schedule, as fans enjoyed their moment with players, chants of "Let's Go Raptors" popping up along the route, players at times spraying supporters with champagne.
"I didn't think there were this many people," Raptors swingman Danny Green said. "It looks like all 37 million of them are here. It's amazing. This is our way of trying to give back to them. It's special.
"It seems like one long day. Nobody has gotten any sleep."
Toronto Mayor John Tory declared Monday "We The North" Day in Toronto, using the team's slogan.
"Myself, everybody here and in Canada, it's a dream come true." said Congolese-born Spaniard Serge Ibaka.
"To me it's just a way to show all the kids how much we love basketball. I used to be one of those kids out there. Look at me today. It's for all of us out there, to let them know anything is possible."
Spanish centre Marc Gasol looked out over the sea of humanity and marvelled at the scene.
"It's what basketball is about, bringing people together for a great cause," Gasol said. "How much joy you see on people's faces. It has been a great ride. I can't imagine a better ending to it."
Crowds were so huge on University Avenue they filled the street and blocked the path of the parade for more than half an hour.
"This is crazy man. I don't know what else to say. It's crazy," said Cameroonian forward Pascal Siakam. "I'm blessed. We're all blessed. It's an amazing moment."
- 'So much energy, buzz' -
Inflatable Raptors balloons and giant signs were waved above the massive crowd.
"There's so much energy, so much buzz," said Raptors reserve Jeremy Lin. "We're definitely very grateful for our fans. This is definitely a once in a lifetime opportunity to enjoy this with our fans."
It was the first title of Lin's nine-year career, the first US player of Chinese or Taiwanese heritage to play in the NBA. Lin wore a purple Raptors jersey with a team logo and Chinese characters.
"It has been an incredible journey," Lin said. "And I've had a lot of fun along the way."
Raptors swingman Norman Powell was at a loss for words.
"Excitement. Joy. So many words for this moment. Can't even describe it right now," he said.
"We love our fans. They fought with us the way we fought. They grinded when we grinded. It's just great to share this moment with them."