Several studies have indicated the potential therapeutic outcomes of combining selective COX-2 inhibitors with tubulin-targeting anticancer agents. In the current study, a novel series of thiazolidin-4-one-based derivatives (7a–q) was designed by merging the pharmacophoric features of some COXs inhibitors and tubulin polymerization inhibitors. Compounds 7a–q were synthesized and evaluated for their cytotoxic activity against MCF7, HT29, and A2780 cancer cell lines (IC₅₀ = 0.02–17.02 μM). The cytotoxicity of 7a–q was also assessed against normal MRC5 cells (IC₅₀ = 0.47–13.46 μM). Compounds 7c, 7i, and 7j, the most active in the MTT assay, significantly reduced the number of HT29 colonies compared to the control. Compounds 7c, 7i, and 7j also induced significant decreases in the tumor volumes and masses in Ehrlich solid carcinoma-bearing mice compared to the control. The three compounds