Kota Tinggi District is a district on the southeastern part of Johor. It takes its name from the town of Kota Tinggi on the banks of the Johor River. Kota Tinggi District covers an area of 3489 square kilometers, making it the biggest district in the state. it is bordered by Mersing District to the north, Kluang District to the northwest, Kulaijaya District to the west, Johor Bahru District and Singapore to the southwest, and the South China Sea to the east.