 Quantum theory is fundamental to contemporary  physics.[1]  It is natural to view a fundamental physical theory as describing or representing the physical world. But many physicists and some philosophers have questioned or rejected this view of quantum theory. They have viewed the theory as concerned with our observation and description of, knowledge or beliefs about, or interactions with the world. Views of this kind have been expressed since the 1920s when quantum theory emerged in close to its present form. This entry is concerned with more recent developments of this tradition by physicists and philosophers, much of it described as quantum-Bayesian or pragmatist. This entry discusses the form of quantum-Bayesianism known as QBism in section 1, addressing common objections in section 2. After section 3 briefly notes pragmatist influences on QBism section 4 sketches a variety of self-described pragmatist approaches to quantum theory, while section 5 mentions some related views.