The Chinese city still does not permit same-sex marriage, but activists have won piecemeal victories that struck down discriminatory government policies on visas, taxes, inheritance and housing.
Here are some key dates:
1991: Decriminalisation
Hong Kong's colonial-era lawmakers in 1991 voted to decriminalise consensual sexual acts between men aged 21 or above, belatedly following Britain's lead.
After the city was handed over to China in 1997, LGBTQ activists found limited success in a legislature packed with Beijing loyalists, and proposals for an anti-discrimination law on the basis of sexual orientation and gender identity went nowhere.
2006-2008: Early successes
The case of Leung TC William Roy, which went to the Court of Appeal, helped lay the groundwork for LGBTQ rights protection under the Basic Law, Hong Kong's mini-constitution.
Appeal judges ruled in September 2006 that the Basic Law and Hong Kong's Bill of Rights should be read in a way that prohibited unlawful discrimination on the basis of sexual orientation.
In the 2008 case of Cho Man-kit, the court said Hong Kong's Broadcasting Authority was wrong to publicly criticise a television documentary that featured same-sex marriage.
2013 onwards: Trans rights
Hong Kong's top court in 2013 ruled in favour of a transgender woman's right to marry -- a stance considered progressive compared with other Asian jurisdictions at the time.
The plaintiff had completed gender confirmation surgery and should count as a woman for the purposes of getting married, which would allow her to marry a man, the judges said.
In 2023, the Court of Final Appeal ruled that a transgender person can apply to change the "sex entry" on their Hong Kong identity card without having to fully complete surgery -- though activists say the government has not fully amended its policy to reflect the court's demands.
2018 onwards: Incremental wins
Legal challenges in the late 2010s showed a pattern of activists targeting smaller wins to increase their chances of success.
Many of their arguments focused on how certain Hong Kong government policies treated same-sex couples differently from opposite-sex couples without good reason.
This led to the Court of Final Appeal siding with same-sex couples on issues such as spousal visas in 2018 and joint taxation in 2019.
2023: Same-sex marriage bid
Jimmy Sham, a pro-democracy activist known for advocating LGBTQ rights, asked the court to strike down Hong Kong's ban on same-sex marriage -- a move considered more ambitious than previous legal bids.
On September 5, 2023, by a 3-2 vote, Hong Kong's top judges rejected same-sex marriage but ordered the government to set up an "alternative legal framework" to protect same-sex couples' rights.
Officials were given a two-year deadline to pass relevant legislation. No bill has yet been tabled.
The government told AFP in September that it was "formulating implementation details" -- but declined to say if a public consultation would be held.
Sham was one of 45 democracy campaigners jailed this year after being found guilty of subversion under a Beijing-imposed national security law, though his case was not directly related to LGBTQ advocacy.
2024: More gains
On Tuesday, Hong Kong's top court ruled against the government to affirm housing and inheritance rights for same-sex couples.
Resident Nick Infinger went to court over a policy that excluded him and his partner from public rental housing on the grounds they were not an "ordinary family".
The case was later heard together with that of Henry Li and his late husband, Edgar Ng, who challenged government policies on subsidised housing and inheritance rules.
The court unanimously dismissed the government's appeals.
