Olusegun Obasanjo takes office as President of Nigeria, the first elected and civilian head of state in Nigeria after 16 years of military rule.

Chief Olusegun Matthew Okikiola Ogunboye Aremu Obasanjo is a Nigerian politician, statesman, and former army general who served as Nigeria's military dictator from 1976 to 1979 and later as its president from 1999 to 2007. Ideologically a Nigerian nationalist, he was a member of the Peoples Democratic Party (PDP) from 1998 to 2015, and since 2018.

The president of Nigeria, officially the president of the Federal Republic of Nigeria, is the head of state and head of government of the Federal Republic of Nigeria. The president directs the executive branch of the Federal Government and is the commander-in-chief of the Nigerian Armed Forces.

A head of state is the public persona of a sovereign state. The name given to the office of head of state depends on the country's form of government and any separation of powers; the powers of the office in each country range from being also the head of government to being little more than a ceremonial figurehead.

Nigeria, officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf of Guinea in the Atlantic Ocean to the south. It covers an area of 923,769 square kilometres (356,669 sq mi). With a population of more than 230 million, it is the most populous country in Africa, and the world's sixth-most populous country. Nigeria borders Niger in the north, Chad in the northeast, Cameroon in the east, and Benin in the west. Nigeria is a federal republic comprising 36 states and the Federal Capital Territory, where its capital, Abuja, is located. The largest city in Nigeria by population is Lagos, one of the largest metropolitan areas in the world and the largest in Africa.