The current study investigates the effect of thermomechanical treatment (TMT) on the fatigue behavior of commercially pure titanium (CP-Ti), with particular focus on conditions that promote dynamic strain aging (DSA). DSA, arising from the interaction between mobile dislocations and diffusing solute atoms, can enhance mechanical strength under specific thermal and strain rate conditions. TMT was applied using both constant and stepwise loading strategies, aiming to induce favorable dislocation structures via DSA. The stepwise TMT approach effectively stabilized the microstructure, particularly around critical stress concentration sites in notched specimens. The stepwise methodology allowed gradual accumulation of plastic strain, promoting a uniform distribution of dislocations and mitigating localized damage. Microstructural investigations using electron microscopy confirmed the presence of dislocation tangling, planar slip bands, and slip-twin interactions—hallmarks of DSA mechanisms. These microstructural features are strongly correlated with improved fatigue resistance, as the controlled dislocation activity enhances the material’s ability to resist crack initiation and propagation. Notably, under stress-intensive conditions such as at the notch root, DSA contributes to the immobilization of dislocations, thereby enhancing local microstructural stability and impeding early crack formation. As a result, crack initiation and propagation will be in higher stress conditions versus the conditions where TMT in DSA temperature was not applied.