Théophile Alexandre Steinlen (1859–1923) was a Swiss-born French Art Nouveau painter and printmaker known for his iconic posters and illustrations, particularly depicting Parisian life in the late 19th and early 20th centuries. Born in Lausanne, Steinlen moved to Paris in 1881, where he became associated with the bohemian Montmartre neighborhood. His art often captured scenes of everyday life, with a focus on working-class subjects, cabaret performers, and cats, as seen in his famous poster "Le Chat Noir" (1896). Steinlen's style blended elements of Realism and Art Nouveau, characterized by bold lines and expressive compositions. His illustrations for newspapers and magazines, such as "L'Assiette au Beurre," contributed to his widespread popularity and established him as one of the leading graphic artists of his time.