We have prepared superconducting Tl-Ca-Ba-Cu-O thin films on a variety of substrates with transition temperatures as high as approx. =120 K, confirmed by sharp onsets of substantial Meissner and shielding signals at the same temperatures. The properties of the films are found to depend sensitively on the post-annealing conditions. Highly textured c-axis-oriented films comprised mostly of Tl/sub 2/Ca/sub 1/Ba/sub 2/Cu/sub 2/O/sub x/, Tl/sub 1/Ca/sub 2/Ba/sub 2/Cu/sub 3/O/sub x/, and Tl/sub 2/Ca/sub 2/Ba/sub 2/Cu/sub 3/O/sub x/ were synthesized by varying the annealing procedure with corresponding maximum superconducting transition temperatures of approx. =100, 110, and 120 K, respectively.