HT-9 steels have lower swelling rate, which makes them a preferred structural material for Generation IV reactors. It is known that microstructural defects can cluster and degrade the overall mechanical properties over the material’s lifetime in a reactor environment. Thus, it is imperative to establish microstructure-property relationships for these alloys and establish the fundamental mechanisms governing material failure. In-situ micro-tensile tests have the potential to improve statistics necessary to evaluate material performance, while reducing the operator dose. However, the representativeness of this technique and its correlation with the meso-scale tests have not been established. In this study, the micro- and meso-tensile properties of as-fabricated HT-9 steels are correlated with the microstructure of the steels using techniques such as, in-situ micro-tensile testing, scanning electron microscopy, and electron backscattering diffraction (EBSD). The yield and ultimate tensile stress of HT-9 calculated from both scales are compared and representativeness of micro-tensile testing is accessed.