According to one embodiment, a memory system includes: a non-volatile memory including blocks each including memory cells; and a memory controller configured to execute a first read process of reading data from a first memory cell in a first block by using a first voltage and a second read process of reading data from a second memory cell in the first block by using a second voltage. The memory controller is configured to: maintain, when a first condition is satisfied, a difference between the first and second voltages at a first value, and change both the first and second voltages; and change, when a second condition is satisfied after the first condition has been satisfied, a difference between the first and second voltages from the first value to a second value, and change at least one of the first and second voltages.