Tl containing Ar, Kr, and Xe matrices were produced by electrode sputtering in a self-igniting pulsed-discharge unit. The absorption and laser-induced fluorescence spectra of the thallium atoms have been investigated. The results are compared with our recent observations of gas phase diatomic thallium-rare gas (Tl-Rg) clusters. The observed linewidths, shifts, and relaxation dynamics are qualitatively interpreted on the basis of the pairwise Tl-Rg interaction potentials.