Up to 1.5 million people have been on the streets of London for the Pride parade, organisers said.
Starting at Portland Place, the parade went across Oxford Circus and down Regent Street before arriving at Whitehall via Trafalgar Square.
This year's event celebrated 50 years since the first Stonewall uprising in New York.
London Mayor Sadiq Khan said he hoped it would be the biggest Pride event to have been held in London.
More than 30,000 people from 600 groups, organisations and businesses were taking part in the event, which this year has a theme of Pride Jubilee.
The Red Arrows carried out a flypast at 13:25 BST.
At the scene: Rebecca Cafe, BBC News
Organisers said they expected 1.5 million people to attend this year's event and although it is hard to say whether that estimate is accurate, all the streets are rammed full of partygoers.
Although the focal point of Pride in London is the main parade that runs from Oxford Street straight down to Whitehall, the celebrations have spread out right across central London, creating a real festival vibe.
On the streets of Soho, there is standing room only as friends congregate and chat while the sound systems blare music out.
Just down the road in Trafalgar Square, revellers wearing an array of colourful outfits are taking turns to parade down a mini catwalk - a pink carpet thrown down on the road.
At a nearby traffic light, a drag artist wearing an outfit fit for a Disney princess graciously posed for endless photos with tourists, while other revellers were decked out in their finest and most colourful outfits.
The parade was due to finish at 17:00, however from the look and sound of things it will be a long time before the celebration dies down.
Don Pepper, who was at London's first pride event said it was very different then.
"There was no dressing up, there was no drag - it was just everyone dressed normally," he said, adding that there were probably about 1,000 people marching then.
"There was abuse from cars whereas now people cheer you on, but then they would tell you to disappear.
"There wasn't any entertainment afterwards, we just sat down and had a picnic and that was it."
All pictures copyrighted.
Update 2nd October 2019: This article has been amended to make clear that estimated attendance figures came from organisers.