The highly conductive copper iodide (CuI) film with excellent thermoelectric (TE) performance could be simply prepared by a solution process using a spray printing technique for transparent and flexible thermoelectric generators (TEGs). The addition of small amount of the iodine (I2) into the CuI solution was dramatically effective in obtaining the excellent electrical conductivity of 207.6 S·cm-1 and power factor of 673.3 μW·m-1·K-2 , resulting in the high zT value of 0.31. Importantly, the I- (ionic state) originated from the I2 played a critical role to increase the electrical conductivity by the growth of crystallites and the attainment of the stoichiometric CuI. The two different flexible TEGs with coiled and foldable shapes were successfully demonstrated, which showed high output power density of 236.5 μW cm-2 at a temperature gradient of 22 oC and the high sensitivity to small changes in temperature of halogen lamp, respectively. This efficient and facile approach suggests the practical strategies to develop the solution processible transparent conductors with high TE performance, as well as, potentially apply to an energy harvestable window or screens for passive houses or buildings.