Paul Cornoyer was an American painter, currently best known for his popularly reproduced painting in an Impressionist, tonalist, and sometimes pointillist style.

Born in St. Louis, Missouri, Cornoyer began painting in Barbizon style, trained at the St. Louis School of Fine Arts, and first exhibited in 1887. In 1889, he continued his studies in Paris at the Académie Julien with Jules Lefebvre, Louis Blanc and Benjamin Constant. While Cornoyer was in Paris, he also traveled to London and Venice. This period exposed him to French Impressionism, which was reflected in a more fluid, tonal and lyrical style in his later landscapes and cityscapes. Cornoyer's interpretation of impressionism was more conservative than his French counterparts, leaving his work with a distinctly American sensibility.

He returned to his home in St. Louis in 1894 and that same year painted a mural at the Planters Hotel which depicted the birth of St. Louis., Cornoyer was heavily influenced by the American tonalists. William Merritt Chase saw examples of Paul Cornoyer's work in Paris during their time there in 1889. Chase later encouraged Cornoyer to leave St. Louis and to travel to New York City. New York City proved an ideal place for Cornoyer to develop his aesthetic. It was there that Cornoyer painted the urban cityscapes for which he is best known. His canvases were tonal depictions of street scenes, especially after a rainfall. Building off his training in the Parisian streets, he was able to capture the essence of city life with its stark pavements, horse drawn carriages with drivers and passengers, as well as tree lined streets, and tall buildings. Examples of Cornoyer's street scenes include Plaza After the Rain and A Rainy Day in the City.

In 1908, the Albright–Knox Art Gallery (formerly the Albright Gallery) hosted a show of his work. In 1909, he was elected into the National Academy of Design as an Associate Academician. He taught at Mechanics Institute of New York and in 1917, he moved to Massachusetts, where he continued to teach and paint.