<p>This paper investigates a Timoshenko system with two fractional damping terms acting on the transverse displacement and rotation angle equations, coupled with a thermoelastic effect governed by the Coleman–Gurtin law for heat flux. Under suitable hypotheses, we prove the decay of the system’s energy and establish the existence and uniqueness of solutions using the Lumer–Phillips theorem. Moreover, we demonstrate strong stability of solutions of polynomial type. The novelty of this work lies in the combined treatment of Coleman–Gurtin thermal effects with double fractional damping and in deriving explicit polynomial decay rates, thereby extending and complementing existing results in the literature. Finally, a numerical example based on a first-mode modal approximation illustrates the dissipative effects of the fractional damping terms and provides qualitative confirmation of the theoretical decay results.</p>