Oswald Külpe (August 3, 1862 – December 30, 1915) was one of the structural psychologists of the late 19th and early 20th century.
He was born at Kandau, Courland, and in 1879 graduated from the Gymnasium at Libau, where he taught for the next two years. Külpe was a student of history at the University of Leipzig when he encountered Wilhelm Wundt and decided to change his major to work with Wundt. When he graduated, he became Wundt's assistant. He was influenced strongly by Wundt, but later disagreed with him on the complexity of human consciousness that could be studied.
At Leipzig, he became somewhat impatient with the strictures that Wundt had placed on what could and could not be studied and left Leipzig for the University of Würzburg. There, he began to practice what he called systematic experimental introspection. His subjects would complete complex tasks and then provide a retrospective account of their cognitive processes during the task. His main finding, known as "imageless thought" seemed to be that thoughts can occur without a particular sensory or imaginal content.
Külpe left Würzburg in 1909. After three years at the University of Bonn, Külpe moved to the University of Munich in 1912. Ernst Bloch and Henry J. Watt were among his pupils.