An actor and a guesthouse owner will make up one of the first same-sex couples to be married in the UK when the new law comes into force.
Andrew Wale and Neil Allard will be married in the music room of the Royal Pavilion, Brighton, just after midnight on March 29 as soon as the law allows.
The couple, who live in Brighton and have been together for seven years, told Brighton and Hove City Council it would be a "privilege" to be the first same-sex couple to be married at a place which features in their daily lives and was the backdrop to their early dates.
Mr Wale, 49, said: "I feel so lucky to live in a country where human rights and equality are moving in the right direction, and in a city with such an impressive history of tolerance and inclusion.
"To be the first same-sex couple to have the opportunity to be married here is a great privilege. We are very excited to be a small part of this huge step forward."
Mr Allard, 48, said: "As well as being the most iconic building in Sussex, the Royal Pavilion has become part of our personal iconography.
"This city will always be a special place for us because it's where we met and fell in love and the Pavilion is the heart of the city."
When the Home Office announced the law would come into effect in March 2014, Brighton and Hove City Council was able to finalise plans to commemorate the date.
The register office invited same-sex couples to apply to be the first to be married in the city and asked them to explain why the Royal Pavilion is special to them and what it would mean to be married in Brighton and Hove's first gay wedding ceremony.
Senior ceremonies registrar Trevor Love said:" This will be a momentous and historic day for the registration service in England and Wales, and for all of those couples making their marriage vows together.
"Brighton and Hove is a popular location for ceremonies and we have been busy keeping people up-to-date with the latest news about the introduction of same-sex marriage.
"It is wonderful to see this law change being welcomed so enthusiastically in the city."
Brighton and Hove is the second most popular location in the UK for civil partnerships, with Westminster coming first.
Figures release by the Office for National Statistics showed 220 same-sex couples took part in civil partnerships in the city in 2012.