A memory device includes a fail test circuit configured to generate a fail flag indicating whether a failure was detected in a column line, on the basis of internal data outputted from the column line selected according to a column address, when performing a test, and control the fail flag to indicate that the failure was detected in the column line, on the basis of a fail control signal. The memory device also includes a repair information generation circuit configured to generate, from the column address, a repair column address for repairing the column line, on the basis of the fail flag.