Copper(II) oxalate are inorganic compounds with the chemical formula CuC2O4(H2O)x.

[3] The anhydrous compound has been characterized by X-ray crystallography.

Copper(II) monooxalates are practically insoluble in all solvents.

[5] Copper(II) oxalate can be produced by precipitation from acidified aqueous copper(II) salts and oxalic acid.

Further heating at higher temperatures under an atmosphere of hydrogen gives copper metal, suitable as a reagent.