Laser shock peening (LSP) is a surface treatment technique focused on improving the mechanical performance of metal components by inducing compressive residual stresses. This research evaluated the effects of LSP on a Ti-6Al-4V alloy, an α + β titanium alloy manufactured by wrought and additive manufacturing used in biomedical and aerospace applications. Samples manufactured by conventional processes and additive manufacturing were treated under the following conditions: Pulse width of 6 ns, wavelength of 1064 nm, scan density of 2500 pulses/cm², pulse energy of 0.750 J, and repetition frequency of 10 Hz. The mechanical response was evaluated in terms of residual stress, microhardness, and microstructure before and after treatment. The results showed significant improvements, reaching compressive residual stress fields of up to −800 MPa and a 22% increase in microhardness, and grain refinement from 18.16 μm to 5.54 μm. These results confirm the effectiveness of LSP in improving the surface integrity and mechanical behavior of Ti64 components, regardless of their manufacturing method.