A new europium-silicon-oxynitride compound EuSi2O2N2 was obtained by a reaction of Eu2O3, SiO2, and α–Si3N4 at 1300 °C under a nitrogen atmosphere. EuSi2O2N2 is indexed on a monoclinic unit cell with a = 13.151(5) Å, b =17.311(5) Å, c = 7.956(2) Å, β = 104.12(4)°, and V = 1756.56 Å3. EuSi2O2N2 shows a highly pure yellow color associated with a very steep drop in the reflection spectrum with an optical absorption edge at about 512 nm (2.43 eV). On the other hand, EuSi2O2N2 can be efficiently excited in the visible range 370–485 nm and shows a broad band emission peaking at about 568 nm corresponding to the Eu2+ 4f65d1 → 4f7 transition. EuSi2O2N2 shows paramagnetic Curie behavior with an experimental magnetic moment of 7.89(3) μB in accordance with 7 unpaired spins of Eu2+. Additionally, no magnetic ordering can be observed down to 5 K. The divalent nature of the Eu ions in EuSi2O2N2 is evident from both luminescence and magnetic properties.