Some things in the world--intentional items such as words, thoughts, portraits, and passport photos--are about things, whereas other things in the world--sticks, stones, and fireflies--are not about anything. Necessary Intentionality is a study of aboutness, or intentionality, with a focus on the following question: are intentional items typically about whatever they are about as a matter of necessity, or is their aboutness, rather, a matter of mere contingency? Consider, for example, a particular name referring to a particular person, or a specific belief with respect to some particular thing that it is such and so. Is it possible for the name not to have referred to the person and for the belief not to have been about the thing? Ori Simchen defends a negative answer to such questions. That the name refers to the person is necessary for the name and that the belief is about the thing is necessary for the belief. Simchen articulates his overall position in two main stages. In the first stage he fleshes out a requisite modal metaphysical background. In the second stage he brings the modal metaphysics to bear on cognition, specifically the aboutness of cognitive states and episodes. Simchen presents a productivist approach, which takes aboutness to be determined by the conditions of production of intentional items, rather than an interpretivist approach that takes aboutness to be determined by conditions of consumption of such items.