Symphony No. 9 in D minor, Op. 125, is a choral symphony, the final complete symphony by Ludwig van Beethoven, composed between 1822 and 1824. It was first performed in Vienna on 7 May 1824. The symphony is regarded by many critics and musicologists as a masterpiece of Western classical music and one of the supreme achievements in the history of music. One of the best-known works in common practice music, it stands as one of the most frequently performed symphonies in the world.

The Ninth was the first example of a major composer scoring vocal parts in a symphony. The final (4th) movement of the symphony, commonly known as the Ode to Joy, features four vocal soloists and a chorus in the parallel modulated key of D major. The text was adapted from the "An die Freude (Ode to Joy)", a poem written by Friedrich Schiller in 1785 and revised in 1803, with additional text written by Beethoven. In the 20th century, an instrumental arrangement of the chorus was adopted by the Council of Europe, and later the European Union, as the Anthem of Europe.