The main monopoly theory developed by Austrian economists, from Menger to Mises, is the theory of monopoly price. However, this theory was later criticized within the Austrian School itself by Rothbard. On the topic of competition, Austrian economists critique standard models, such as perfect and monopolistic competition, for overlooking the dynamic and entrepreneurial nature of market processes. The chapter challenges the static assumptions of these models by highlighting instead entrepreneurial competition as a process of discovery, essential to the functioning of markets. Advertising, product differentiation, and cost-cutting are reframed as competitive, not monopolistic, elements.