<p>Mullite refractory ceramics are extensively used in high-temperature industrial applications. To enhance their performance in terms of increased strength and toughness, aimed at curbing the intrinsic brittleness and low fracture strength of monolithic ceramics, most researchers have employed the addition of sintering additives, whiskers and fibers as reinforcing media while producing mullite-based refractory ceramics. This review shows that the development of mullite-based refractory ceramics with the addition of sintering additives, second-phase particles, whiskers and fibers has achieved significant improvements in their mechanical strength and toughness. The review outlines the suitability of various kaolin clays as sources of mullite refractories, highlighting an overview of mullite ceramics with a detailed discussion on various mechanisms that enhance the mechanical strength and fracture toughness of these ceramics. It also highlights the current state-of-the-art technologies including spark plasma sintering, sol-gel impregnation, additive manufacturing (3D printing and direct ink printing), the use of industrial waste-derived aluminosilicates, bio-derived additives and nano-structured reinforcements, being employed in the production of refractory ceramics, to achieve tailored properties (intricate shapes and improved morphology), reduce production time, conserve the environment, and achieve reduced costs.</p>