<p>Additively manufactured Ti6Al4V requires post-processing to attain improved mechanical properties compared to as-forged and wrought counterparts for higher specific strength applications. Taking into account the significance of β transus temperature of titanium alloys, annealing temperature is found to significantly influence mechanical behavior and microstructural features. In this study, a comparative analysis on compression behavior and impact toughness of wire arc additively manufactured Ti6Al4V as a function of sub-transus, super-transus, and repeated recrystallization annealing has been carried out to investigate the effect of different annealing conditions on mechanical behavior of Ti6Al4V under compressive and impact loading conditions. The compression test results on ultimate compressive strength, yield strength, and specific energy absorption capability of as-forged, as-built, and annealed Ti6Al4V revealed that sub-transus annealing exhibited 18.98%, 10.37%, and 16.04% improvement, respectively, compared to as-built part. Moreover, microstructural study unveiled that the decomposition of finer acicular α laths into the globularized α and α + β lamellar microstructure of sub-transus annealed Ti6Al4V is found to result in an optimal balance between compressive strength and deformability. The 81.52% broadening of α lath width through the boundary-splitting mechanism caused significant improvement in grain sphericity, aspect ratio, and effective slip length. Furthermore, sub-transus annealing of Ti6Al4V is found to slightly deteriorate the impact toughness from 28.5 ± 1. to 23.5 ± 1.18&#xa0;J due to the reduction of grain misorientation and dislocation density that lead to decreased dislocation nucleation and migration. Therefore, sub-transus annealing of Ti6Al4V can be anticipated as the optimum heat treatment condition to achieve better compression behavior than its as-forged counterpart.</p> Graphical abstract <p></p>