In this paper, Ti-doped ZnO nanostructures are synthesized using citric acid sol-gel (citrate route) method. Synthesized nanostructures are calcined at two different temperatures; 400 and 600 °C. A comprehensive study of the effect of Ti incorporation on the crystal structure, nanostructures size, shape, and elemental composition, as well as the optical properties of the doped ZnO nanostructures is reported. Mixed phases of hexagonal ZnO and cubic ZnTiO₃ are detected at high Ti concentrations (≥12%) and calcination temperatures of 600 °C. This is further confirmed by optical studies where absorbance as well as diffuse reflectance edges characteristic of ZnTiO₃ are detected. XRD studies confirm the successful doping and provide a clear indication that Ti is replacing the Zn atoms substitutionally. Doped ZnO morphology changed from nanoflakes to nanostructures with porous nature as Ti content increases. EDX analysis shows the Ti content to increase as the Ti/Zn molar ratio increases in the synthesized samples. The optical bandgap is found to be sensitive to the Ti content and can be tuned by varying the Ti concentration.