Supramolecular chemistry offers new routes for creation of carbon and graphene-based materials with precise control of structure. This approach stacks, aligns, polymerizes, or otherwise directs the assembly of precursor molecules into non-covalent superstructures or macromolecular intermediates that are then chemically converted to carbon. A subset of this field uses liquid crystal phases, or mesophases, which exhibit orientational molecular order somewhere along the chemical trajectory to carbon. Covalent capture of that orientational order followed by heteroatom removal leads to “mesogenic graphenic materials”. This review article addresses these carbons and focuses on new methods and materials that use well-defined molecular precursors. It discusses polyaromatic compounds as starting materials, assembly modes in the melt and solvent phases, and potential applications.