Susurluk is a small town and a district of Balıkesir Province in northwestern Turkey. It is famous for its production of soap and dairy products. The highway from İstanbul to İzmir passes through Susurluk. In Turkey Susurluk is known for 'tost' - a toasted cheese sandwich with tomato paste and for its foamy ayran. The population was 23,995 in 2010. The mayor is Hüseyin Hızlıoğlu (AKP).
On 3 November 1996 a car crash in the town made news headlines as the dead and injured included a parliamentary deputy, a right-wing gang leader, a former beauty queen and a senior police officer.
The resulting political and social turmoil has come to be known as the Susurluk scandal, and the accident was described as definite proof of a link between politics, organized crime and the bureaucracy, known in Turkish as the derin devlet ("deep state").
Several people, including three former special forces members, were convicted of illegal activities and served prison terms.