Ketu is the name of a Yoruba subgroup, historical kingdom and region straddling parts of what is now southeastern Republic of Benin and parts of southwest Nigeria. The chief town and traditional capital of the area was the town of Kétou (Kétu), which is considered to be one of the oldest capitals of the Yoruba-speaking people, tracing its establishment to a settlement founded by a descendant of Oduduwa (also known as; Odùduwà, Oòduà and Eleduwa) called Sopasan or Soipasan. The Oba of the town were traditionally styled "Alákétu", and are related directly to Ile-Ife in present-day Nigeria.
Other towns that were historically part of the Kétu Kingdom are;
- Ilara-Ogudo Yewa - Straddling the Nigeria-Benin international border (Nigerian side)
- Ilara Kanga - Straddling the Nigeria-Benin international border (Benin side)
- Iwoye ketu - Imeko Afon Local Government, Ogun state, Nigeria
- Ewé / Adakplamé - Plateau Department, Benin
- Ijoun - Imeko Afon Local Government, Ogun state, Nigeria
- Kpankou (Panku) - Plateau Department, Benin
- Ijale Ketu - Imeko Afon Local Government, Ogun state, Nigeria
- Ijaka - Yewa North Local Government, Ogun state, Nigeria
- Idigny (Idiyin) - Plateau Department, Benin
- Igan Alade - Yewa North Local Government, Ogun state, Nigeria
- Imeko - Imeko Afon Local Government, Ogun state, Nigeria
- Illikimou - Plateau Department, Benin
- Egua - Imeko Afon Local Government, Ogun state, Nigeria
- Ebute Igboro - Yewa North Local Government, Ogun state, Nigeria
- Imoto - Imeko Afon Local Government, Ogun state, Nigeria
- Owode Ketu - Yewa North Local Government, Ogun state, Nigeria