The number of organisations participating in the event on Saturday increased by more than 250, or 25%, from the previous year.
A brief shower just before the parade began did not dampen enthusiasm, and the sun quickly reappeared as bright floats travelled through the streets of the city in a carnival-like atmosphere.
The throng lined the path, waving flags, included both young and old people.
Stand By Your Trans was the theme of Belfast Pride 2023, and trans, non-binary, and gender-diverse persons lead the march.
John O'Doherty, co-chairman of Belfast Pride, claimed the gathering was openly trans-inclusive.
He said that the message had a part in the significant attendance.
“Pride has been growing year over year, but I think particularly this year our message really resonated with people,”
“The Stand By Your Trans message is such an important one, and it allows people to lend their voice to a campaign that so many of us support but haven't had the capacity or vehicle to be able to show our full support behind.”
The attention in the run-up to this year's event had been on who wasn't going, despite the record number of registrations.