SiC-matrix composites consist of ceramic fibers embedded in a silicon carbide matrix produced by gas-, liquid-, or solid-phase routes, yielding materials that differ in matrix crystallinity, residual porosity, and thermal properties. These composites can be highly engineered in terms of the nature of the reinforcement, the interphase used to control the fiber-matrix bonding, the matrix, and the seal coating used. SiC-matrix composites are refractory ceramics displaying outstanding mechanical and thermal properties at high temperature. Their durability in oxidizing atmospheres and under load exceeds 1000 h at temperatures of up to ∼1200°C. They have been used to fabricate different components of the hot zone of jet engines with significant weight savings and an increase in performance. This article reviews the state of the art in the processing, materials design, and properties of these composites as well as their applications in advanced jet engines.