Idah is a town in Kogi State, Nigeria, on the eastern bank of the Niger River in the middle belt region of Nigeria. It is the headquarters of the Igala Kingdom, whose traditional ruler, the Attah Igala, Alhaji Aliyu Obaje died in July 2012.

Idah is also a smaller Local Government Area with an area of 36 km² around the town and a population of 79,815 at the 2006 census.

The postal code of the area is 271.

Idah, an old river port, lies on the eastern bank of the river Niger at 7°05′00″N 6°45′00″E / 7.0833333°N 6.75°E / 7.0833333; 6.75. It has commercial routes on the river Niger linking Lokoja, the Kogi state capital, to the north of the country and Onitsha in Anambra state) to the south, Agenebode Edo State across the Niger to the west. Its population is primarily Igala.

Idah hosts a federal polytechnic. The Federal Government College Ugwolawo is also within the periphery of Idah. Idah is a major food supplier of Kogi State and the traditional capital of the Igala kingdom.