The chemical preparation, structure, luminescence, and electronic properties are given for a new potassium holmium cyclotetraphosphate KHoP4O12, a promising optics material for applications. Single‐crystal X‐ray diffraction analysis shows that the newly synthesized compound crystallizes in the monoclinic system with space group C2/c and Z = 4. [P4O12]4– anionic rings and HoO8 polyhedra display a three‐dimensional (3D) framework by corner‐sharing. The ten‐coordinated potassium atoms are located in the delimited tunnels. KHoP4O12 exhibits the blue light emission under the excitation of 330 nm. To gain further insights into electronic properties of crystal KHoP4O12, theoretical calculation based on density functional theory (DFT) was performed using the total‐energy code CASTEP with the LDA + U approach. The calculated bandgap with U = 3.0–3.5 eV is in good agreement with the experimental measurement.