The woman said her visa had been denied after her same-sex relationship was not recognised.
Hong Kong’s court of appeal has ruled that a British lesbian who moved to the territory with her partner should be granted a dependent visa.
The visa, usually given to the husbands and wives of foreigners working in Hong Kong, was denied because she was not considered a spouse, the woman said.
Same-sex marriage is banned in the territory although discrimination based on sexual orientation is illegal.
Campaigners say this is a landmark case that could lead to greater equality.
The woman, who has been identified as QT, entered into a civil partnership in England in 2011 after more than seven years with her partner.
In the same year, the couple moved to Hong Kong after QT’s partner was offered a job there.
QT said that applications to the Immigration Department had been rejected after officials refused to recognise her UK-registered partnership.