Ilesha, town, Osun state, southwestern Nigeria. It lies in the Yoruba Hills and at the intersection of roads from Ile-Ife, Oshogbo, and Akure. The town is one of the oldest settlements in Yorubaland—according to tradition, it was founded by an owa (“king”) who was one of the 16 sons of the deity Oduduwa. Ilesha was an important military centre in the campaigns against Ibadan, 60 miles (97 km) west-southwest, in the 19th-century Yoruba civil wars, and the town has a memorial to Ogedengbe, an Ileshan warrior-leader who died in 1910.
Modern Ilesha is a major collecting point for the export of cocoa and a traditional cultural centre for the Ilesha (Ijesha) branch of the Yoruba people. Palm oil and kernels, yams, cassava (manioc), corn (maize), pumpkins, cotton, and kola nuts are collected for the local market. Local industries manufacture nails and carpets, and the town has a brewery; there are also a recording company and a publishing firm. Several prominent quartzite ridges lie east of Ilesha, and gold mining is an important activity in the area.
Ilesha is the site of several teacher-training colleges. Near the Market Square are the traditional king’s palace (the Afin), the central mosque, and the principal park. Pop. (2006) local government area, 210,141.