Corrections officers were asked not to attend, because of the department's record on transgender rights.
The landmark parade ended at Waitangi Park, for the 31st annual Out in the Park.
Wellington Pride chair Adrienne Girling greeted the exhuberant crowd, telling them the parade was a major moment for them.
"We just took the streets back, Wellington.
"It's amazing to see you fill up the park like this.
"We've grown exponentially in the last few years, have had an amazing response from the community, and it wouldn't be possible without support from you in the community."
Mayor Justin Lester also spoke to the crowd, first taking a selfie so he could prove "how much pride festival is growing."
"We're tremendously proud of our Pride community.
"We support LGBTQI rights, we want to do more for the trans community, and to make sure every school in Wellington is safe.
"We want to have a city where everyone feels loved, everyone feels safe, everyone feels secure."