"The National Anthem" is the name of a song by the band Radiohead.

A national anthem is a generally patriotic musical composition that is formally recognized by a country's government as their state's official national song.

During the course of the 19th and 20th centuries, with the rise of the national state, most countries adopted a national anthem, which in some cases coexists with other commonly sung patriotic songs. The oldest song purporting to be a national anthem is the "Wilhelmus" from The Netherlands, it was written between 1568 and 1572 during the Eighty Years' War. It is unusual among national anthems, in that it that it does not refer to a country but to a monarch. More typically, anthems seek to reflect the unity of a nation by galvanzing the history, traditions and struggles of its people.

As anthems first rose to prominence in Europe in the nineteenth century the style of music common then has continued to be used in almost every national anthem. Even in nations of Africa and Asia, where western orchestral music was a foreign notion, the national anthem is still usually in European style. Only a handful of non-European countries have anthems rooted in indigenous traditions, most notably Japan (which has the oldest anthem in the world, Kimigayo), Iran, Sri Lanka, and Myanmar.

Some other countries have challenged the dominance of dated orchestral music. In Australia, for instance, the official anthem since 1984 has been "Advance Australia Fair", but there is much support for the folk ballad "Waltzing Matilda" as a national song, even a candidate for the national anthem. Certainly, more Australians know all the words of the latter song.

The majority of national anthems are either marches or hymns in style. The countries of Latin America tend towards more operatic pieces, while a handful of countries use simple fanfare. Because of their brevity and need for relative simplicity, most national anthems are of little interest musically. Some of the notable exceptions are the anthems of the USSR, the EU, Germany and Hungary.

Few anthems have been written by notable composers. The French anthem "La Marseillaise" was written by the otherwise unknown Claude Joseph Rouget de Lisle; the tune of "The Star-Spangled Banner" was taken from "To Anacreon in Heaven" by the otherwise unknown Englishman John Stafford Smith; and "God Save the Queen" was written by a composer whose identity to this day is not known with any certainty at all. While the music to the German anthem was written by Joseph Haydn to the words "Gott erhalte Franz den Kaiser," it became notorious during the Nazi era as "Deutschland, Deutschland über alles."

Amongst the very few countries to have an anthem written by a world renowned composer are: Germany, which uses one by Joseph Haydn; and the Vatican City, whose anthem was written by Charles Gounod. Similarly, few anthems have been praised for having lyrics of great poetry, although the noted poet Rabindranath Tagore wrote the lyrics both for the Indian and for the Bangladeshi national anthems.

National anthems are used in a wide array of contexts. Universally they are played on national holidays and festivals. They have also come to be closely connected to sporting events. At the Olympics the national anthem of the gold medal winner is played at each medal ceremony. National anthems are also played before games in many sports leagues. In some countries the national anthem is played to students each day at the start of school. In other countries the anthem is played in a theatre before a play or in a cinema before a movie. Many television stations have adapted this and play the national anthem when they sign on in the morning and again when they sign off at night.

Many states also have unofficial anthems, and countries may also have royal anthems, presidential anthems, state anthems, or anthems for sub-national entities that are also officially recognized.

Larger entities also sometimes have anthems. The tune of the Ode to Joy from Beethoven's Symphony No. 9 is the official anthem of the European Union; the United Nations and the African Union also have unofficial anthems.