Example embodiments may provide a memory device and memory data reading method. The memory device according to example embodiments may include a multi-bit cell array, an error detector which may read a first data page from a memory page in the multi-bit cell array and may detect an error-bit of the first data page, and an estimator which may identify a multi-bit cell where the error-bit is stored and may estimate data stored in the identified multi-bit cell among data of a second data page. Therefore, the memory device and memory data reading method may have an effect of reducing an error when reading data stored in the multi-bit cell and monitoring a state of the multi-bit cell without additional overhead.