The New York City Police Department (NYPD), the largest police department in the US, has primary responsibility for law enforcement and investigation within the five boroughs of New York City It is considered to be the first "modern" style police department in the US; when it was created in the 19th century it was modeled after London's Metropolitan Police.

One Police Plaza is the headquarters of the NYPD located on Park Row across the street from City hall. According to the department, its mission is to "enforce the laws preserve the peace, reduce fear, and provide for a safe environment." Primarily, this involves preventing and responding to crime.

The New York City Transit and Housing Police were fully integrated into the NYPD in 1995 some new police officers are randomly assigned to the Transit and Housing units. NYPD members are frequently referred to by the nickname New York's Finest (in the same vein as FDNY firefighters are called New York's Bravest.