Paul Klee Notebooks is a two-volume work by the Swiss-born artist Paul Klee that collects his lectures at the Bauhaus schools in 1920s Germany and his other main essays on modern art. These works are considered so important for understanding modern art that they are compared to the importance that Leonardo's A Treatise on Painting had for Renaissance. Herbert Read called the collection "the most complete presentation of the principles of design ever made by a modern artist – it constitutes the Principia Aesthetica of a new era of art, in which Klee occupies a position comparable to Newton's in the realm of physics."

Paul Klee was a Swiss-born German artist. His highly individual style was influenced by movements in art that included expressionism, cubism, and surrealism. Klee was a natural draftsman who experimented with and eventually deeply explored color theory, writing about it extensively; his lectures Writings on Form and Design Theory, published in English as the Paul Klee Notebooks, are held to be as important for modern art as Leonardo da Vinci's A Treatise on Painting was for the Renaissance. He and his colleague, Russian painter Wassily Kandinsky, both taught at the Bauhaus school of art, design and architecture in Germany. His works reflect his dry humor and his sometimes childlike perspective, his personal moods and beliefs, and his musicality.