The Nigerian Army (NA) is the land force of the Nigerian Armed Forces. Tracing its history to British colonial forces in West Africa, it is the largest component of the armed forces. The President of Nigeria is the Commander-in-Chief of the Nigerian Army, and its professional head is the Chief of Army Staff, who is the highest ranking military officer of the Nigerian Army. It is governed by the Nigerian Army Council (NAC). The Nigerian Army is operationally and geographically divided into ten divisions, the basic field formation. The army has been involved in operations throughout the country, most especially during the Nigerian Civil War, and has undertaken major operations abroad. Nigerian Army officers have served as chiefs of defence in other countries, with Brigadier General Maxwell Khobe serving as Sierra Leone chief of staff in 1998–1999, and Nigerian officers acting as Command Officer-in-Charge of the Armed Forces of Liberia from at least 2007.

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.