The effects of growth temperature on the microstructure evolution and electrical transport properties of Cu2O films were investigated. Nanocrystalline Cu2O films with modest p-type semiconducting properties (Hall mobilities ∼20 cm2/Vs, hole concentrations ∼1016 cm−3) were successfully prepared at room temperature without post-annealing. Bottom gate and top contact p-channel Cu2O thin-film transistors (TFTs) were constructed on flexible polyethylene terephthalate substrates at room temperature, which shows superior transfer performance (field effect mobility ∼2.40 cm2/Vs and current on/off ratio ∼3.96 × 104). The low processing temperature and the good electrical performance of the p-type Cu2O TFTs suggest their good potential for applications in high-throughput and low-cost electronics.