A range of alloying candidates have been identified for beta gallium oxide (β-Ga2O3) as a means of tuning its electronic properties, primarily the band gap. Scandium has been recognized as a promising alloying candidate, but its effect on β-Ga2O3’s electronic, structural, and defect behavior must be better understood to enable further development. Here, Czochralski-grown (100) β-(Sc0.06Ga0.94)2O3 crystals were investigated using atomic-resolution scanning transmission electron microscopy, monochromated electron energy loss spectroscopy, and first-principles simulations. These results show that Sc preferentially occupies octahedral Ga sites, and increases the material’s band gap from 4.8 eV to 4.92 eV when alloyed with 10 mol % Sc. It is also demonstrated that the alloying of Sc can result in unique extended defect formation in both intrinsic and mechanically deformed β-(Sc0.06Ga0.94)2O3. The structure of a unique planar defect in the as-grown crystal was determined to be a set of closely spaced, (100)-oriented stacking faults resulting in a unique atomic projection. Mechanical deformation of the crystal, performed to help understand intrinsic defect structure, resulted in the identification of a new atomic configuration within a stacking fault heavily influenced by local strain, which we term a “strained stacking fault”. No widespread formation of point defects or dislocations was observed in the as-grown crystal. These results reveal the ability for unique extended defects, such as multiple stacking faults in close proximity, to be formed in β-Ga2O3 systems when alloyed. These findings provide insight into the potential of β-(ScxGa1-x)2O3 alloys to produce substrates with a range of electronic and structural properties, enabling further development of β-Ga2O3 for next generation power semiconductor applications.