The Thinker (French: Le Penseur), by Auguste Rodin, is a bronze sculpture depicting a nude male figure of heroic size, seated on a large rock, leaning forward, right elbow placed upon the left thigh, back of the right hand supporting the chin in a posture evocative of deep thought and contemplation. This universally recognized expression of "deep thought" has made the sculpture one of the most widely known artworks in the world. It has become the iconic symbol of thinking; images of the sculpture in profile are often used to indicate philosophy and other practices of contemplation or introspection.

Rodin conceived the figure as part of his work The Gates of Hell commissioned in 1880, but the first of the familiar monumental bronze castings was made in 1904, and is now exhibited at the Musée Rodin, in Paris.

There are 27 other known full-sized bronze castings of the figure, approximately 185 centimetres (73 in) tall, though not all were made under Rodin's supervision. Various other versions, several in plaster, as well as studies and posthumous castings, exist in a range of sizes.