Infrared (IR) spectra of resorcinol (Rs)-Ar-n clusters (n = 1 and 2) have been measured in the neutral and cationic ground states (S-0 and D-0) by IR dip and resonance-enhanced multiphoton ionization (REMPI)-IR spectroscopy. The OH stretching vibrations in S-0 keep their frequency regardless of the number of Ar atoms and the conformation of the OH groups in Rs (rotamers RsI and RsII), demonstrating that the Ar atoms are attached to the aromatic pi-ring (pi-bound structure) in S-0. In the D-0 state, the IR spectra of Rs(+)-Ar-n reflect the difference in the Rs conformations (RsI(+) and RsII(+)). For n = 1, the IR spectra of both rotamers are almost the same as those of the corresponding monomer cations, indicating that Ar ligands essentially remain g-bonded after ionization. In contrast, the IR spectra of Rs(+)-Ar-2 show hydrogen-bonded and free OH stretching vibrations, demonstrating that for a significant fraction of the clusters, the Ar atoms migrate from the pi-bound site to the OH groups. The ionization-induced pi -> H migration yields are not unity for both rotamers RsI(+)-Ar-2 and RsII(+)-Ar-2. This result is in sharp contrast to phenol(+)-Ar-2, in which one of the Ar atoms migrates to the OH site with 100% yield. The mechanism leading to the nonunity yield in Rs(+)-Ar-2 is discussed in terms of the number of OH binding sites and Franck-Condon factors. The ionization excess energy dependence of the IR spectra of Rs(+)-Ar-2 and its Rs(+)-Ar fragments is discussed in terms of the Ar binding energies estimated from the photoionization and photodissociation efficiency spectra.