A new cocrystal formed between the nutraceutical compounds pterostilbene and theophylline was synthesized and X-ray characterized in the form of a dichloromethane solvate. An interesting supramolecular assembly is formed by means of a combination of common and uncomment π–π and H-bonding interactions. It was computationally studied by a combination of density functional theory (DFT), quantum theory of “atoms-in-molecules”, and noncovalent interaction plot approaches, and the analyses revealed a π(C═C)···H-bond array interaction, which is the first description of this type of interaction where the donor π-system is a double bond. The participation of the cocrystallized CH₂Cl₂ solvent molecule in Cl···Cl and C–H···π interactions was also studied using DFT and Hirshfeld surface calculations. The Cambridge structural database was inspected to investigate whether the π···H-bond array interaction is common in other theophylline cocrystals. Other examples where the π-system of an aromatic ring or an amido group interact with the H-bond array were found in literature and further discussed herein.