5,10,15,20-Tetrakis(4-pyridyl)porphyrin (TPyP) is a symmetric, highly conjugated macrocyclic compound featuring a porphyrin core with four peripheral pyridyl groups. This structure endows it with strong light absorption, fluorescence, and the ability to coordinate with various metal ions to form metalloporphyrins. Its primary applications are in advanced materials science. As a functional building block, it is widely used to construct metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), where it acts as a rigid, photoactive linker or node. These porous materials find use in gas storage, catalysis, and chemical sensing. Furthermore, TPyP and its metal complexes are investigated as key components in organic electronics, including organic light-emitting diodes (OLEDs), organic photovoltaics (OPVs), and as photosensitizers in photodynamic therapy (PDT) research. The compound is also utilized as a catalyst or catalyst precursor in oxidation reactions and as a supramolecular building block for creating complex nanostructures and thin films due to its self-assembly properties.