<p>Excellent magnetostrictive properties and processability are the two most important key factors for the practical application of magnetostrictive materials and research directions of continuous concern. In this study, we significantly improved the magnetostriction, ductility, and tensile strength of Fe₈₃Ga₁₇B_<i>x</i> (<i>x</i> = 0, 1, 2, 3, and 4) alloys by adjusting the small-radius boron (B) doping concentration. When <i>x</i> = 3, the maximum magnetostriction value reached 193&#xa0;ppm, approximately twice that of the undoped alloy (<i>x</i> = 0), while the ultimate tensile strength and elongation increased by 147% and 238%, respectively, compared to Fe₈₃Ga₁₇ alloys. Both first-principles calculations and experimental results indicate that B doping facilitates the alignment of FeGa crystal growth direction with the easy magnetization axis, thereby significantly improving the magnetostrictive properties of the alloy. Additionally, increasing B content progressively refines the grain size and promotes Fe₂B phase formation, thereby enhancing both strength and toughness. At <i>x</i> = 3, the material exhibits the highest saturation magnetization and the lowest coercivity. Therefore, the results show that doping small-radius atoms in the interstitial sites can effectively enhance the magnetostrictive and mechanical properties of FeGa materials. This work offers a promising strategy for designing magnetostrictive materials with superior overall properties.</p> Graphic abstract <p></p>