Kawkhali upazila (Rangamati) on the north, Chandanaish, Patiya and Boalkhali upazilas on the south, Kaptai, Rajasthali and Bandarban sadar upazilas on the east, Raozan and Kawkhali upazilas on the west.

Rangunia thana was turned into an upazila in 1983. The upazila consists of 11 union parishads, 71 mouzas and 149 villages.

Rangunia Upazila is located in Chittagong District. Upazilla(s)/Thana(s) in Chittagong are Anwara Upazila, Bandar (Chittagong Port) Thana, Banshkhali Upazila, Boalkhali Upazila, Chandanaish Upazila, Chandgaon Thana, Double Mooring Thana, Fatikchhari Upazila, Hathazari Upazila, Kotwali Thana, Lohagara Upazila, Mirsharai Upazila, Pahartali Thana, Panchlaish Thana, Patiya Upazila, Rangunia Upazila, Raozan Upazila, Sandwip Upazila, Satkania Upazila, Sitakunda Upazila.

Remnants of the palace of Chakma King Shukdev Ray (18th century), Ranir Pond (Raja Hat), remnants of the palace of Chakma Queen Kalindi (1844), Pagla Mama's Dargah (19th century) and Dharmo Chakra Vihara (1750).