Tractatus Logico-Philosophicus (Logico-Philosophical Treatise) is the only philosophical work published by Ludwig Wittgenstein during his lifetime. Today, it is considered one of the most important philosophical texts of the 20th century, inaugurating a new direction in philosophy that concerned the analysis of language.

The "Logical-Philosophical Treatise" served as the "Bible" of the Vienna Circle and was also a significant influence on the Cambridge analysis school in the 1920s and 1930s. It inspired the movement of logical positivism, which in turn was the most influential philosophical movement of the 20th century.

After completing it, Wittgenstein believed he had solved all the traditional problems of philosophy, which he abandoned for about a decade. This work is characterized as one of the most enigmatic philosophical texts of all time, inspiring extensive literature, yet there is no general agreement on its interpretation.