Crime in Sydney has been varied and extending to historical time.

From its earliest days with a prison camp Sydney has maintained a healthy scepticism of authority. The Rum corps was probably Sydney's first taste of organised crime.

Sydney developed into a major sea port. The combination of penal colonies, corrupt authorities and gold rushes, and increasing wealth encouraged the growth of a criminal element.

Criminal behaviour remains a problem in many parts of Sydney today. Whilst relatively good by world standards, the city is noteworthy crime spot in Australia, with a higher crime rate than Melbourne, for instance.

Perhaps the most notorious place in Sydney in terms of criminal history is Kings Cross in inner eastern Sydney. It has a long history of illegal gambling clubs, sex clubs, paedophilia, drug dealing, "shooting galleries", police corruption and murder. It remains the backdrop of the mysterious disappearance in 1975 of Juanita Nielson, an heiress who opposed high-rise development there. The Wood Royal Commission in the 1990s found widespread corruption amongst the police at Kings Cross, and several were forced to resign.

Other problem areas in Sydney include the western suburbs of Cabramatta (which became notorious in the 1990s for illegal drugs being openly sold in its streets and at its railway station by juvenile drug dealers, and for a political assassination in 1994), Punchbowl and Lakemba (focal points of much ethnic tension and ethnic-based crime) and the southern inner city suburb of Redfern (known for a politically-sensitive failure called the 'Block', where the streets can be so hostile that taxi drivers and pizza delivery drivers have refused to travel).

In the summer of 2000 a series of four gang rapes occurred, in which gangs of up to 18 men violently abducted and raped women. In every case, the men were of Lebanese Muslim descent, and the women of European descent. The incidents polarized the city and led to harsh new sentences for gang rape in New South Wales.