Karacabey is a municipality and district located in the Bursa Province of Turkey. Covering an area of 1,158 km2, it has a recorded population of 84,907 as of 2022. The district is situated just west of the Simav River near its confluence with the Adirnaz River.
The geographical boundaries of Karacabey are defined by several neighboring districts: Mudanya and Nilüfer to the east, Mustafakemalpaşa and Susurluk to the south, Manyas to the southwest, and Bandırma to the west. Historically, the district is noted for being sited on the ancient town of Miletopolis.