Based on a simple model of a hole self-trapped in a VK-center-like configuration, the lattice relaxation, internal optical transition energies, and thermal activation energy for hopping of the self-trapped hole in solid argon are calculated. It is found that the molecular binding of Ar2+ is the predominating factor for the stability of this mode of self-trapping. The optical transition energies are found to be smaller than the corresponding energies in alkali halides. The most interesting result is about the activation energy for hopping which is smaller than 0.05 eV. It is suggested that the self-trapped hole in crystalline argon should be produced and studied at very low temperature, below about 20 °K.