Intruder (French: L'Intruse) is a one-act play by Belgian playwright Maurice Maeterlinck, which appeared first in publication in 1890. Journalistic appreciations of the text throughout that year prompted Parisian independent theatre producers to get the performance rights. From its stage debut the following spring, it became identified as a landmark work in the Symbolism movement of the late-nineteenth century. Intruder concerns man's conflict with preternatural forces, against which he is powerless. The same theme was prevalent in Maeterlinck's earlier play, Princess Maleine, published 1889.