Lanthanum oxalate is an inorganic compound, a salt of lanthanum metal and oxalic acid with the chemical formula La2(C2O4)3.

[1][2] Reaction of soluble lanthanum nitrate with an excess of oxalic acid: Also, a reaction of lanthanum chloride with oxalic acid: Lanthanum(III) oxalate forms colorless crystals that are poorly soluble in water.

[3] The compound forms various crystallohydrates La2(C2O4)3•nH2O, where n = 1, 2, 3, 7, and 10.

[4][5] The crystallohydrates decompose when heated.

[6]