An overview of chemically bonded phosphate ceramics (CBPCs), that fill the gap between cements and conventional ceramics, is provided. CBPCs are synthesized by chemical reactions, most of them at ambient conditions, and hence are most useful in high volume applications. These applications include stabilization of hazardous and radioactive wastes, various structural materials applications, including road repair, oil well cements, and architectural products. The products are mainly magnesium and iron-phosphate ceramics. Specialty formulations have also been developed for biomaterials applications using calcium-phosphate-based ceramics. This article reviews the chemistry of syntheses of these materials, using magnesium iron and aluminum phosphate ceramics as representative examples, provides a summary of their properties and an overview of their niche applications.