The rallies, which once attracted tens of thousands of people, ended in 2020 after the introduction of national security laws as well as Restrictions related to COVID.
On Wednesday, police officers patrolled in Victoria park, where a small fair sold food and other goods, without referring to the events of June 4, 36 years ago.
In recent years, monuments and books related to repression have been removed from public spaces by the Hong Kong authorities.
When asked if people were allowed to commemorate the birthday, the chief of the executive John Lee said that all the activities were to comply with the law.