We synthesized and characterized a series of four closely related thiourea derivatives (1–4) obtained by reaction of 4-R-benzoyl chloride (R: H, Cl, CH₃, and OCH₃) with equimolar amount of potassium thiocyanate and dibenzylamine in dry acetone. The crystalline and molecular structures of the synthesized compounds 1–4 were examined to understand how the crystal packing of each compound altered when substituted by different functional groups at para position on the aromatic ring. Single-crystal X-ray diffraction analysis revealed that molecules of the prepared compounds assembled into supramolecular units connected via networks of similar intermolecular interactions. The packing arrangement of the compounds, however, was found to be different. We also conducted Hirshfeld surface analysis for all the synthesized compounds and followed the changes of different properties on these surfaces related to systematic variations of the substituent. Hirshfeld surface analysis and decomposed fingerprint plots showed that the structures were stabilized by H···H, H···S, O···H, N···H, C–H···π, and π···π intermolecular interactions, which contribute mostly to the packing of the species in the crystal. The two largest contributions to the packing of the molecules in the crystals were provided by H···H (51.6, 39.5, 54.4, and 51.4 %) and C–H···π (27.4, 27.1, 24.6, and 28.8 %) intermolecular interactions.