This paper examines the mechanical properties of two high strength titanium alloys as a function of test temperature, namely, the α/β titanium alloy Ti-6A1-6V-2Sn (Ti-662) as well as the metastable β-alloy Ti-8Mo-8V-2Fe-3A1 (Ti-8823). Specifically, the paper characterizes the changes in fracture toughness and tensile properties at low and elevated test temperatures. The variation in fracture toughness is given by K_Q and W/A, while for the tensile properties, it is given by the yield and ultimate tensile strength, reduction of area, and elongation. For Ti-8823 material, the characterization was conducted on material that was given either a solution treated-and-aged or an age treatment directly after fabrication. Heat treatments for the Ti-662 alloy were either a solution-treated-and-age or solution-treated-and-overaged. Results are discussed in terms of fractographs taken from broken fracture toughness and tension specimens.