[en] It is of vital importance to capture lanthanides (nuclear fission products) from waste solutions for radionuclide remediation owing to their hazards. The effective separation of lanthanides are achieved by an acid/base‐stable and radiation‐resistant vanadate, namely, [Me${}_2$NH${}_2$]V${}_3$O${}_7$ (1). It exhibits high adsorption capacities for lanthanides (q${}_m$${}^{Eu}$=161.4 mg g${}^{\text{â<!-- ?? -->}\text{ˆ<!-- ?? -->}\text{’<!-- ??? -->}1}$; q${}_m$${}^{Sm}$=139.2 mg g${}^{\text{â<!-- ?? -->}\text{ˆ<!-- ?? -->}\text{’<!-- ??? -->}1}$). And high adsorption capacities are maintained over a pH range of 2.0–6.9 (q${}_m$${}^{Eu}$=75.1 mg g${}^{\text{â<!-- ?? -->}\text{ˆ<!-- ?? -->}\text{’<!-- ??? -->}1}$ at low pH of 2.5). It displays high selectivity for Eu${}^{3+}$ (simulant of An${}^{3+}$) against a large excess of interfering ions. It can efficiently separate Eu${}^{3+}$ and Cs${}^{+}$ (or Sr${}^{2+}$) with the highest separation factor SF${}_{Eu/Cs}$ of 156 (SF${}_{Eu/Sr}$ of 134) to date. The adsorption mechanism is revealed by calculations and XPS, EXAFS, Raman, and elemental analyses. These merits combined with facile synthesis and convenient elution makes the title vanadate a promising lanthanide scavenger for environmental remediation. (© 2020 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)