The 2026 Sydney Gay and Lesbian Mardi Gras marks 48 years since the first gay rights parade in 1978, and follows an announcement the historic route will be added to Australia's National Heritage List.
For 78er Karl Zlotkowski, who has taken part in every Mardi Gras, the heritage listing is something he never imagined 50 years ago.
"You have to remember, in 1978 we didn't set out to actually start this extraordinary thing - it just happened and all of us almost became involved by accident," he told AAP.
"The parade route is deeply, deeply special to the 78ers because it's where they were born ... it's a symbolic heart of Sydney in many ways and that's why it's wonderful to see that it's acknowledged nationally as part of Australia's history."
Forecast rain is not expected to dampen spirits, with hundreds of thousands expected to turn out to cheer on 170 floats and almost 10,000 participants as they take to Oxford Street.
Among them will be James Shields III. taking part in the Emerald City Kickball Australia float, which will close out the parade.
Dressed to impress as a sequined prawn, to fit with the float's theme of "shrimps on the barbie", Mr Shields said nothing short of blood, sweat and tears goes into parade organisation.
"We've learned that if you put a bunch of creatives into a room, you're never surprised by the fantastic, phenomenal thing that they'll produce," he said.
"Seeing our community come together and their ideas come to life and that it's well-received is just such an empowering experience."
Originally from New Orleans, a city known for its own Mardi Gras celebrations, Mr Shields said Sydney's parade was something special.
"The city actually shows that they support what's happening (and) so many parts of the community live for it, so it feels community-led and community-driven," he said.
"Seeing (the parade) come to life, it's like a walking museum of all the self-expressive individuality and creative ideas."
After sunset, six planets will align in the evening sky, an intergalactic event CSIRO senior engineer Suzy Jackson said reflected the Mardi Gras Ecstatica Galactica theme.
"We have six of our planets - unfortunately Mars never got the memo - showing up for a planetary alignment that we'll be able to see if you look west just after the sun goes down," she said.
"Essentially this happens because all of the planets are spinning around the sun in their different orbits and occasionally they do happen to line up, but it's pretty cool that we're getting a nice planetary alignment for our celebrations."
With multiple city roads to be closed for the celebrations, police have urged people to use public transport which will run on a 24-hour timetable.
There will be extra train services running late at night and early in the morning to help people get home safely, but commuters are urged to plan ahead as not all lines will run frequent services.
Uniformed and plain clothes officers will patrol the CBD and surrounding suburbs to manage expected large crowds, Assistant Commissioner Stephen Hegarty said.
"Police will focus on providing a reassuring presence to the community, support crowd movement and target criminal and anti-social behaviour which undermines the celebratory and respectful spirit of the night," he said.
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