The term national army typically means the lawful army of the state, as distinct from rebel armies or private armies that may operate there.

National Army may also refer to:

National Revolutionary Army, the national army of the Republic of China in 1925–1947, known has the National Army after 1928

Korean Liberation Army, the national army of the Republic of Korea in 1941–1946, known has the National Army after 1943

National Army, the 1917 army of the United States of America

National Army (Ireland) (1921–1924), the army of the Irish Free State in its formative years

Suriname National Army, the name of the Surinamese military since 1980

Nationalist faction (Spanish Civil War), (Spanish: Ejército Nacional), Nationalist rebel forces in the Spanish Civil War

Syrian National Army, Syrian opposition group

National Army of Colombia, the land military force of the government of Colombia and the largest service of the Colombian Armed Forces

Armed Forces of Guatemala, (Spanish: Ejercito Nacional de Guatemala), a branch of the military of Guatemala

National Army of Uruguay, (Spanish: Ejército Nacional), a branch of the military of Uruguay

National Army of Venezuela, one of the four professional branches of the Armed Forces of Venezuela

Libyan National Army, military forces of the Libyan House of Representatives