A public security bureau (PSB; Chinese: 公安局; pinyin: gōng'ānjú) of a city or county, or public security department (PSD; Chinese: 公安厅; pinyin: Gōng'āntīng) in a province or autonomous region of the People's Republic of China is a generic term for a police department.

According to the State Council, the official duties of public security bureaus are:

Public security bureaus and public security departments act as the main civilian police agency of their city or province, respectively. Under public security bureaus are police stations (Chinese: 派出所; pinyin: pàichūsuǒ).

The chief of a provincial public security department is also typically a deputy provincial governor.

The system of public security bureaus is administered by the Ministry of Public Security (MPS), which co-ordinates the work of provincial public security departments that are also answerable to the local governments and provincial party secretaries.

Each province/autonomous region has a public security department, while each municipality (Including directly administered municipalities like Beijing or Tianjin) has a public security bureau. Counties and county level cities also have smaller PSBs. Districts have branches(Chinese: 公安分局; pinyin: Gōng'ān fèn jú), also known as subbureaus, in contrast to counties and county level cities.

The PSB system does not apply to the special administrative regions of Macau and Hong Kong, as they have their own police forces, the Hong Kong Police Force and the Public Security Police Force of Macau, respectively.

Units of a PSB vary from agency to agency, though most bureaus have a traffic police unit, a SWAT unit, a crime investigation unit, a legal affairs unit, a food safety and environmental crime unit, a detention center/jail and a public order unit, though functions of each unit also vary, For example, in the Daishan County PSB, the Public Order unit is also in charge of food safety, while in the Shenzhen Municipal PSB there is a separate unit for Food Safety and environmental crime.