Lynch rode in the parade on a double-decker bus with Warriors forward Draymond Green. Lynch, who rarely speaks to reporters, even did an interview afterward with CSN Bay Area, standing with Green's mother.
"This is very big for me," Lynch said. "It's been a while. I don't think I've seen a championship in Oakland. Being part of a parade is cool for me."
He said the Warriors remind him of the "brotherhood" the Seahawks have.
Lynch attended Game 1 of the NBA Finals at Oracle Arena as the Warriors started the series with a 108-100 victory over the Cleveland Cavaliers. Lynch had a conversation with Golden State coach Steve Kerr.
"I told Coach Kerr, 'You gotta go get a championship,'" Lynch said Friday. "I can't be the only one from Oakland with a championship."
People started lining up as early as 3 a.m., and city officials estimated at least 500,000 fans packed the streets when the parade started about 10 a.m.
Information from The Associated Press was used in this report.