Judging from the dates of creation of states in the country, Cross River, Lagos, Kaduna, Kano, Kwara and Rivers states respectively are the oldest states in Nigeria.
These six states were all formed on the 27th of September, 1967.

Nigeria Education and Information Portal
Judging from the dates of creation of states in the country, Cross River, Lagos, Kaduna, Kano, Kwara and Rivers states respectively are the oldest states in Nigeria.
These six states were all formed on the 27th of September, 1967.