Kailahun is the capital of Kailahun District in the Eastern Province of Sierra Leone. Kailahun is a rural town and is a major agricultural and business center. The population was 13 108 in the 2004 census, and a current estimate is 14 085. Kailahun lies approximately 75 miles north-east of Kenema and about 300 miles (by road) east of Freetown
The population of Kailahun is largely from the Mende ethnic group and the Mende language is widely spoken in the town. The town is a political stronghold of the Sierra Leone People's Party (SLPP), the main opposition party in Sierra Leone.