Titanium alloys continue to be vital structural materials for various aerospace as well as non-aerospace applications. There is a strong motivation to develop technologies that can reduce the processing costs and increase the performance of conventional titanium alloys to enhance the affordability and expand their usage. Small boron additions to conventional titanium alloys have shown significant promise in this direction. The physical metallurgy of boron-modified titanium alloys (Ti-B) will be briefly described, including compositions, phases, processing, microstructures, and properties. It has been established that trace (~0.1 wt%) boron addition dramatically refines the cast grain size by an order magnitude. The grain refinement could lead to reduction/elimination of processing steps and also provides opportunities to design novel and affordable processing paths. Addition of boron of the order of 1 wt%, on the other hand, significantly (25-30%) increases the strength and stiffness of conventional Ti alloys at room as well as elevated temperatures without causing debit in fracture related properties. Better understanding of the processing-microstructure-property relationships has been found to be the key in the development of Ti-B alloys for aerospace applications where fatigue and damage tolerance are critical factors. Research and development programs that are currently underway at the Air Force Research Laboratory, aimed at exploring and establishing the benefits of boron addition to Ti alloys will be reviewed.