Experimental results obtained previously for vdW-bonded and H-bonded phenol...argon (PhOH...Ar) complexes in their S(0) and D(0) states are combined with ab initio quantum-chemical theoretical results. Such a combination allows us to present a "complete" description of the geometry, relative energies, interaction energies and enthalpies of PhOH...Ar complexes. Based on a minimum-energy-path study, the transition structures and barrier heights related to transitions between stable conformers are also presented. For the presented structures, the agreement between the theoretical interaction enthalpy at 0 K with experimentally obtained values is very good. On the other hand, for numerical harmonic-frequency calculations we find a very poor performance for the neutral PhOH...Ar complex and complete failure for the studied complexes in their cationic form.