Fundamentals of Mean Field Theories of Liquid Crystals offers a clear and comprehensive introduction to mean field approaches for understanding liquid crystalline systems, with a focus on rod-like molecules and polymeric liquid crystals. These theories form the foundation for describing the rich phase behavior of anisotropic fluids, which underpin soft matter physics and advanced materials science. Beginning with the classical Onsager and Maier–Saupe theories, the book develops a unified framework connecting microscopic molecular interactions with macroscopic ordering phenomena. It guides readers through the statistical mechanics of orientational order and phase transitions, extending naturally to biaxial nematic and cholesteric phases, field-induced phase transitions, liquid crystalline gels, and self-assembled liquid crystals. This book is primarily intended for senior undergraduate and graduate students, as well as academic researchers in physics, chemistry, and materials science. Key Features:Introduces liquid crystalline phases, orientational order, and phase separations with many useful figuresDevelops mean field models for uniaxial and biaxial nematic, smectic, cholesteric, and columnar phases, and explores phase transitions under external fieldsExtends models to polymer liquid crystals and binary mixturesHighlights phase transition phenomena in liquid crystalline gelsExamines self-assembled liquid crystals and their theoretical treatment