Many of the demonstrators said they were energised after Germany voted last week to legalise gay weddings.
Northern Ireland remains the only part of the UK or Ireland still to make the change to marriage laws.
The colourful parade through the city centre saw gay rights activists joined by trade unions, politicians and famous faces including The Fall actress Bronagh Waugh and Lord Mayor Nuala McAllister.
John O’Doherty, director of the Rainbow Project, which helps gay, bisexual and transgender people, led the demonstrations.
Photo By Kurt Löwenstein Educational Center International Team from Germany (qe07 (9)) [CC-BY-2.0], via Wikimedia Commons
