L'Oiseau de feu (English: The Firebird; Russian: Жар-птица) is a 1910 ballet by Igor Stravinsky based on the Russian folk tales of the magical glowing bird (see Firebird) that is both a blessing and doom of its captor.

The music was premiered as a ballet by Diaghilev's Ballets Russes, the first of their productions with music specially composed for them. The ballet has historic significance as Stravinsky's breakthrough piece, and as the beginning of the collaboration between Diaghilev and Stravinsky that would also produce Petrushka and The Rite of Spring.

Stravinsky's ballet centers on the journey of its hero, Prince Ivan. Ivan enters the magical realm of Katschei the Immortal; all of the magical objects and creatures of Katschei are herein represented by a chromatic descending motif, usually in the strings. While wandering in the garden, he sees and chases the Firebird. The Firebird, once caught by Ivan, begs for its life and ultimately agrees to assist Ivan in exchange for eventual freedom.

Next, Prince Ivan sees thirteen princesses, with whom he falls in love. The next day, Ivan chooses to confront Katschei to ask to marry one of the princesses; the two talk and eventually begin quarreling. When Katschei sends his magical creatures after Ivan, the Firebird, true to its pledge, intervenes, bewitching the creatures and making them dance an elaborate, energetic dance (the "Infernal Dance"). The creatures and Katschei then fall asleep; however, Katschei awakens and is killed by the Firebird. With Katschei gone and his magic broken, the magical creatures and the palace all disappear, and all of the "real" beings (including the princesses) awaken and, with one final fleeting appearance from the Firebird, celebrate their victory.

The chapter in the animated film Fantasia 2000 based on Stravinsky's piece takes an unrelated approach, telling the story of a spring Sprite and her companion Elk. After a long winter the Sprite attempts to restore life to a forest but accidentally wakes the Firebird spirit of a nearby volcano. Angered, the Firebird proceeds to destroy the forest and seemingly the sprite. She is restored to life after the destruction and the forest life is reborn with her. The Fantasia 2000 Firebird chapter is considered an exercise in the theme of life-death-rebirth deities; the depiction of the Firebird in it as a violent, flaming volcanic spirit is not related to Stravinsky's original theme.

Stravinsky's work has had a great deal of influence in musical genres outside of classical. Throughout their career, the progressive rock group Yes have opened their live concerts with an excerpt from the Firebird, and their 1975 song "The Gates of Delirium" is heavily influenced by musical ideas pioneered by Stravinsky.