High-entropy ceramics is an emerging class of high-entropy materials with properties superior to conventional ceramics. Recent research has been focused on the development of new high-entropy ceramic compositions. High-entropy oxides, carbides, borides, silicides, and boron carbides had been reported with superior mechanical, oxidation, corrosion, and wear properties. The research work on the processing and characterization of bulk high-entropy ceramics and coating systems has been summarized in this chapter. The composition design, structure, chemistry, composite processing of bulk high-entropy ceramics, and evolution of microstructure and properties are reported. The literature on the deposition of high-entropy ceramic coating and the influence of coating parameters have been discussed to produce high-entropy ceramic coatings with superior mechanical, oxidation, and wear properties.