Several Ti-15Mo ingots were evaluated with differing oxygen additions in an effort to identify material / process conditions that may achieve a combination of high strength and ductility without the standard thermal aging process, which is common for beta titanium alloys.  The aim oxygen concentrations were 0.12, 0.35 and 0.5 weight percent.  The material was hot rolled to 13 mm (0.5 inch) round bar, and the beta transus temperature was determined for each composition.  Oxygen additions raised the beta transus temperature from approximately 775ºC (1425ºF) for Ti-15Mo-0.12O to 910ºC (1675ºF) for Ti-15Mo-0.5O.  The bar material was thermally processed after hot rolling with annealing temperature and cooling rate as variables, and the influence of these variables was assessed with respect to microstructure and tensile properties.  Room temperature tensile and notched tensile tests with a stress concentration factor of 3.2 were conducted for numerous material / process conditions.  Oxygen was shown to be a potent solid solution strengthener while ductility was maintained at high levels for specific process conditions.  Yield strength values below 620 MPa (90 ksi) were achieved for the alloy with a 0.12 oxygen level while yield strength values as high as 1310 MPa (190 ksi) were obtained for the alloy with 0.5 weight percent oxygen without using aging treatments.  All of the alloy variations demonstrated notch sensitivity when solution treated above the beta transus temperature with a subsequent slow cooling cycle.  However, very little cooling rate sensitivity was noted for alpha/beta annealing processes.  High strength material conditions with a good balance of ductility and notch sensitivity were identified that did not require complex or lengthy aging treatments.