The oxonitridoberyllate Eu3Be22N16O was synthesized from Eu(NH2)2, Be3N2 and BeO in a W crucible under N2 atmosphere in a radio‐frequency furnace at 1400 °C. The crystal structure was solved and refined from X‐ray diffraction data (C2/c (no. 15), a=20.620(2), b=8.722(6), c=17.506(2) Å, β=120.782(3)°) and confirmed with Rietveld refinement methods as well as lattice‐energy calculations (Madelung part of lattice energy, MAPLE). Eu3Be22N16O consists of a rigid network of edge‐sharing BeX4 (X=N, O) tetrahedra and trigonal‐planar BeN3 units resulting in a high degree of condensation κ=1.29. The charge of the anionic network is compensated by Eu2+. Magnetic susceptibility measurements exhibit Curie‐Weiss behavior above 2 K with an effective magnetic moment of 7.82 μB/f.u., which is in accordance with the theoretical value for EuII.