This article discusses the development of a nanocrystalline magnesium alloy, Mg97Zn1Y2, using rapidly solidified powder metallurgy (RS P/M) processing. This alloy exhibits exceptional mechanical properties, including a tensile yield strength above 600 MPa, high ductility, and excellent elevated-temperature strength. The alloy's tensile yield strength ranges from 480 to 610 MPa, with elongation between 5 and 16%, depending on the consolidation temperature. The specific tensile yield strength of the alloy is four times higher than that of the commercial AZ91-T6 alloy and surpasses conventional titanium and aluminum alloys. The alloy also demonstrates high-strain-rate superplasticity over a wide range of strain rates (1 × 10−2 to 1 × 106 s−1) at a relatively low temperature of 623 K. The alloy's microstructure consists of fine hcp-Mg grains and homogeneously dispersed nanocrystalline Mg24Y5 compound particles, contributing to its high strength. The RS P/M Mg97Zn1Y2 alloy is identified as a promising lightweight structural material for applications requiring high strength at both ambient and elevated temperatures, along with good workability.This article discusses the development of a nanocrystalline magnesium alloy, Mg97Zn1Y2, using rapidly solidified powder metallurgy (RS P/M) processing. This alloy exhibits exceptional mechanical properties, including a tensile yield strength above 600 MPa, high ductility, and excellent elevated-temperature strength. The alloy's tensile yield strength ranges from 480 to 610 MPa, with elongation between 5 and 16%, depending on the consolidation temperature. The specific tensile yield strength of the alloy is four times higher than that of the commercial AZ91-T6 alloy and surpasses conventional titanium and aluminum alloys. The alloy also demonstrates high-strain-rate superplasticity over a wide range of strain rates (1 × 10−2 to 1 × 106 s−1) at a relatively low temperature of 623 K. The alloy's microstructure consists of fine hcp-Mg grains and homogeneously dispersed nanocrystalline Mg24Y5 compound particles, contributing to its high strength. The RS P/M Mg97Zn1Y2 alloy is identified as a promising lightweight structural material for applications requiring high strength at both ambient and elevated temperatures, along with good workability.