A memory device and a memory peripheral circuit are provided. The memory peripheral circuit includes a redundancy column data circuit and a column selection control circuit. The redundancy column data circuit is configured to provide a redundancy test mode data signal and a column address signal. The column address signal includes a redundancy column address signal. The column selection control circuit includes a column decoder and a redundancy column decoder. The column decoder disables a bad column address of a main memory block according to the redundancy test mode data signal and the redundancy column address signal. The redundancy column decoder latches the redundancy column address signal, compares the column address signal with the latched redundancy column address to obtain a comparison result, and enables a redundancy column address of a redundancy memory block according to the comparison result.