Composites are, in general, a rapidly evolving and growing technical field with a very wide range of applications across the aerospace, defence, energy, medical and transport sectors as a result of their superior mechanical and physical properties. Ultra-high temperature ceramic matrix composites, UHTCMCs, are a new subfield within the wider grouping of CMCs that offer applications in rocket and hypersonic vehicle components, particularly nozzles, leading edges and engine components. The design and development of structural materials for use in oxidising and rapid heating environments at temperatures above 1600°C is therefore of both great scientific and engineering importance. UHTC materials are typically considered to be the carbides, nitrides, and borides of the transition metals, but the Group IV compounds (Zr, Hf & Ti) plus TaC are generally considered to be the main focus of research due to the superior melting temperatures and stable high-melting temperature oxide that forms in situ . This review presents the selection, processing, properties, applications, outlook and future directions of UHTCMCs.