In the early twentieth century, around 400 Muslim employees from Pakistan and India worked for Hong Kong's Prison Department. They were a substantial community within the colonial prison service, and like any Muslim community, they needed access to regular prayer. For years, they made do with Jamia Mosque in the city center, not far from the department's headquarters on Arbuthnot Road in Central. Then the department moved its headquarters to Stanley, on the far southern coast of Hong Kong Island — a long journey from the city's mosques. The commute that had been manageable became impossible for daily prayer. Rather than require officers to choose between their faith and their work, the department built a mosque on site. It opened on the first day of 1937, the same year as the prison it serves.

Stanley Mosque is the fourth mosque constructed in Hong Kong — a city whose Muslim population has roots stretching back to the earliest years of British colonial rule, when South Asian soldiers, police officers, and civil servants arrived as part of the imperial apparatus. The Jamia Mosque in Mid-Levels dates to 1915; the Shelley Street Mosque to an even earlier era. Stanley came later, purpose-built not for a neighborhood congregation but for a specific occupational community within a specific institution. That particularity is unusual. Most mosques serve the broadest possible community. Stanley Mosque was designed from the start for the men who worked the walls and corridors of a maximum-security facility, a detail that gives the building its peculiar dignity.

In 2009, the Antiquities Advisory Board designated Stanley Mosque a Grade I historic building — the highest category of recognition Hong Kong grants to structures of outstanding significance. The designation acknowledges both the building's architectural integrity and its place in the history of Hong Kong's Muslim community. The mosque's sandy exterior, large prayer hall, open veranda, and courtyard represent a restrained but considered design, one that has remained largely intact since 1937. That it sits inside a prison has not diminished its status; if anything, the survival of the structure through decades of institutional use and renovation pressure around it makes the designation more meaningful.

For more than twenty years, the mosque's imam has been Hafiz Afzal Khan. He leads the prayers, teaches Quran to the congregation, and maintains the continuity of religious life within a setting that does not encourage continuity of any kind. The congregation remains small and specialized: Correctional Services Department staff, most of them with roots in South Asia, who carry forward the same community purpose that built the mosque in the first place. Visitors from outside can enter, but access is controlled by the Correctional Services Department, and the mosque's location means it never draws casual foot traffic. Those who come to pray come because they mean to.