Idukki is the largest district of Kerala, India in area. The district headquarters are located at Painavu. Other largest towns in Idukki are Thodupuzha and Kattappana .

Idukki is greatly known for the splendid green mountains and streams. It is also a main tourist center in Kerala as it has many resorts and hill stations . The famous resort Thekkady (Periyar Tiger Reserve), is in Idukki District. Madupatty , one of the tourist resorts and the headquarters of the Indoswiss Cattle Project is also located in Thekkady. Munnar is another hill resort of the district and Madupatty is about 11 km away from Munnar.

Idukki also has the largest arch dam in India, the Idukki Dam , constructed for the Idukki Hydro Electric Power Project in 1969 with the cooperation of the Canadian Government. This single project powers the entire state and some parts of neighbouring states.