Ernst Theodor Amadeus Hoffmann (born Ernst Theodor Wilhelm Hoffmann; 24 January 1776 – 25 June 1822) was a German Romantic author of fantasy and Gothic horror, a jurist, composer, music critic, and artist. He is best known for the novella The Nutcracker and the Mouse King, which inspired Pyotr Ilyich Tchaikovsky's famous ballet The Nutcracker. Additionally, his stories form the basis of Jacques Offenbach's opera The Tales of Hoffmann, where Hoffmann appears (heavily fictionalized) as the hero. The ballet Coppélia is based on two other stories he wrote, and Schumann's Kreisleriana is based on his character Johannes Kreisler.

Hoffmann's works were highly influential in the 19th-century literature and he remains a major figure of the Romantic movement.