A data strobe buffer and a memory system including the data strobe buffer are provided. The data strobe buffer includes: a first input/output node; a first driver coupled to the first input/output node, the first driver configured to output a first data strobe signal to the first input/output node during a write operation; and a first receiver coupled to receive a second data strobe signal from the first input/output node and output a third data strobe signal during a read operation when the data strobe buffer is in a first or second mode, the first receiver configured to compare the second data strobe signal with a first reference voltage and output a result of the comparison as the third data strobe signal when the data strobe buffer is in the first mode, the receiver further configured to not compare the second data strobe signal with the first reference voltage when the data strobe buffer is in the second mode.