Brighton Pride has announced that "with a heavy heart" the festival has been cancelled this year due to the coronavirus pandemic.
Mariah Carey had been due to headline festival this summer, playing Pride in the Park on Saturday 1 August.
The three-day event was due to run from 31 July to 2 August. On Sunday, The Pussycat Dolls - who recently reformed - were the headline act.
Brighton Pride said the decision "had not been taken lightly"
A Pride spokesman said: "It is with a heavy heart that Brighton and Hove Pride have taken the difficult decision to postpone our landmark 30th anniversary celebrations."
He said the organisers had decided to cancel after evaluating the additional pressure the event would put on the emergency services.
Paul Kemp, director of Brighton Pride, said: "It's been inevitable.
"We are postponing the anniversary celebration to next year and [for] anyone who has got a ticket for the park we'll roll that ticket over.
"Pride is a celebration for the whole city and brings lots of people in, and of course the emergency services, the police, the NHS and all the other key workers who are often part of that parade," he said.
"Our focus is on supporting them and supporting people who are going through tough times."
Alan Robbins, chairman of Brighton and Hove City Council's tourism, equalities, communities and culture committee, said: "It's a great shame.
"The message is going out 'Don't come to Brighton' and we very much want to make sure when this is over everybody does come back to Brighton.
"We're doing everything we can to make sure these things go ahead next year."
Last year, Kylie Minogue headlined the festival, and in 2018 Britney Spears wowed a crowd of 57,000 with the more than 250,000 people visiting the city.