Additive manufacturing (AM) of nickel superalloys typically leads to large columnar grains forming along the build direction, resulting in poor and anisotropic tensile performance. In this work, a novel AM process involving directed energy deposition (DED) combined with in-situ rolling was applied to fabricate a typical nickel superalloy – Inconel 718. The results revealed hierarchical layered refined grains formed in the microstructure, due to the unique dynamic and meta-dynamic recrystallization induced by the in-situ rolling during DED. Through this, an average grain size of ∼8 µm and much weaker texture was achieved for the in-situ rolled samples. Tensile test showed that a significant increase of over 50% in the yield strength was achieved for the in-situ rolled samples at both room temperature and 650°C, while maintaining a good uniform elongation above 10%. •A rolling-assisted DED process has been applied to fabricate Inconel 718 superalloy.•Columnar to equiaxed transition of grains is achieved.•The refined grains (∼8 µm in size) exhibited hierarchical layered distribution.•Over 50% yield strength increment is achieved at both room temperature and 650°C. Display omitted .