In this work, the intermolecular interaction between phenol and gamma-butyrolactone (GBL) has been studied by a combination of spectroscopic and computational techniques. The electronic and vibrational transitions of phenol center dot GBL were measured in a supersonic jet expansion by resonant two-photon ionization (R2PI) and ion dip IR (IDIR) spectroscopy. The results obtained were compared with calculations carried out with both M06-2X and MP2 molecular orbital methods in order to characterize the intermolecular interactions. The singly detected conformer is stabilized by a relatively strong hydrogen bond in which phenol acts as a proton donor to the carbonyl group of GBL. The phenol center dot GBL(2) cluster has also been studied, finding up to three populated conformers. Nevertheless, in the three species, the main interaction between the phenolic hydroxyl group and the GBL's carbonyl group remains similar to that of phenol center dot GBL. Furthermore, the C=O center dot center dot center dot H interaction is reinforced.