Thomas Wilmer Dewing (May 4, 1851 – November 5, 1938) was an American painter working at the turn of the 20th century. He is best known for his tonalist paintings, a genre of American art that was rooted in English Aestheticism. Dewing's preferred vehicle of artistic expression is the female figure situated in a moody and dreamlike surrounding. Often seated playing instruments, writing letters, or simply communicating with one another, Dewing's sensitively portrayed figures have a detachment from the viewer that keeps the spectator a remote witness to the scene rather than a participant.
Tonalism as a style resisted the dogma of modernism and abstraction in art, although the political success of modernism eventually succeeded in branding tonalism as an outdated mode of artistic expression in popular culture. Now that the dogma of Modernism itself is under question, a fresh assessment of tonalism is underway, free of political sway.