This study focuses on the preparation of TiO2/Zn thin films using the d.c. magnetron sputtering technique. The impact of annealing on their structural and optical properties was investigated. The XRD analysis confirms the formation of a pure anatase TiO2 phase. Notably, the anatase phase remains stable even after the annealing process. The XRD results also confirm the crystalline nature of the samples, with distinct peaks at 2θ = 25.2°, 37.19°, 47.57°, 55°, and 62.2° corresponding to (101), (004), (200), (211), and (220) planes, respectively. Fluorescence spectroscopy indicated that the annealing process significantly altered the optical characteristics of thin films. The pristine TiO2/Zn thin films exhibited a broad emission peak in the visible region, centered around 420 nm. Annealing at 300 °C induced notable changes in the fluorescence spectrum, characterized by a reduction in the intensity of the broad emission peak. Further, annealed at 400 °C, the emission peak at 420 nm was significantly diminished, and a new peak emerged at around 480 nm. FTIR analysis provided valuable information on the structural changes and chemical composition of the films. The spectra showed that films annealed at 400 °C exhibited improved crystallization and the presence of surface hydroxyl groups, which are essential for enhanced photocatalytic and hydrophilic activity. AFM analysis demonstrated the effects of annealing on the morphology of films. The as-deposited films had a smooth surface with minimal roughness, but annealing increased roughness and promoted better structural development. In summary, annealing at 400 °C enhances the structural and optical characteristics of TiO2/Zn thin films. These improvements make the films suitable for use in advanced applications. They hold significant potential in areas such as photocatalysis, optoelectronics, and energy storage.