A facile synthesis method of delafossite-type CuYO2 using a layered yttrium hydroxide (LYH) was developed. LYH microplates and Cu2O nanoparticles were both prepared from aqueous solutions and used as raw materials for the solid-state reaction to form CuYO2. It was found that CuYO2 could be obtained by heating LYH-Cu2O mixed powder at 900 degrees C for 4 h under a N-2 atmosphere. Although the product contained a slight amount of Y2O3, the heating time used in the proposed method was much shorter than that required for the conventional synthesis method via the Cu2Y2O5 precursor phase. Analysis of the X-ray diffraction pattern showed that the CuYO2 powder synthesized using LYH contained the 3R-type polymorph as the major content, whereas a larger content of the 2H-type polymorph was included in the powder synthesized by the conventional method. Based on these results, a topotactic reaction maintaining the layered structure of LYH was proposed as the formation mechanism for CuYO2 in LYH-Cu2O mixed powder.