Polycrystalline ceramic/single-walled carbon nanotube (SWNT) composites possess unique grain boundaries, containing 1 D tortuous SWNTs bundles that form 2D tangled embedded nets. This unprecedented grain-boundary structure allows tailoring of multifunctional ceramic/SWNTs composites with unique combinations of desirable mechanical (toughness, strength, creep) and transport (electrical, thermal) properties. A brief discussion and analysis of recent developments in these composites are presented. composites are presented.