Buca is a municipality and district of İzmir Province, Turkey. Its area is 178 km2, and its population is 522,404 (2022). It is the biggest district of İzmir Province as terms of population. It covers the southeastern part of the agglomeration of İzmir and the adjacent countryside.

İzmir Province is a province and metropolitan municipality of Turkey in western Anatolia, situated along the Aegean coast. Its capital is the city of İzmir, which is in itself composed of the province's central 11 districts out of 30 in total. To the west, it is surrounded by the Aegean Sea, and it encloses the Gulf of Izmir. Its area is 11,891 square kilometres, and its population is 4,462,056 (2022). Neighboring provinces are Balıkesir to the north, Manisa to the east, and Aydın to the south. The traffic code of the province is 35.