Calcium-ion batteries are promising candidate as alternative to lithium-ion batteries with appealing features of abundant resource and high theoretical specific capacity up to 1337 mAh g−1. However, the development of calcium-ion batteries is primarily hindered by the lack of satisfactory electrode materials due to the large radius and charge density of calcium ion. Herein, we report the reversible calcium ion intercalation in layered potassium vanadate K2V6O16·2.7H2O as stable cathode with impressive electrochemical performance for Ca ion battery. The potassium vanadate nanowires obtained by facile hydrothermal process (typical lengths of 0.5–1.5 μm, widths of 70–100 nm) deliver a high initial capacity of 113.9 mAh g−1 at current density of 20 mA g−1 and high capacity retention of 78.30% at 50 mA g−1 after 100 cycles. In addition, the reversible intercalation of calcium ion in this layered potassium vanadate material with stable crystal structure is verified by ex-situ XPS and XRD techniques, demonstrating that layered K2V6O16·2.7H2O could be a potential cathode material for calcium-ion batteries. Display omitted •Layered potassium vanadate K2V6O16 is investigated as Ca-ions battery cathode.•High discharge capacity of 113.9 mAh g−1 with retention of 78.3% were achieved.•Reversible Ca2+ insertion/extraction and high structure stability were verified.