The City of Zrenjanin occupies, by its square area, the biggest territory in the AP of Vojvodina and it is the second city by the size of its territory in the Republic of Serbia (after Kraljevo). The square area of the City of Zrenjanin is 1,326 km2, which represents around 8 % of the total square area of AP of Vojvodina and 15% of the square area of Banat, which belongs to Serbia. Out of the area that belongs to the City of Zrenjanin, 82.5% represent agricultural land.

The city consists of Zrenjanin proper with 22 settlements. The City of Zrenjanin borders with the municipalities of Kikinda (on the north), Žitište and Sečanj (on the east), Opovo and Kovačica (on the southeast), Belgrade city municipality of Palilula (on the south), Titel and Žabalj (on the west), and Novi Bečej (on northwest).