A line memory device includes a plurality of memory cells, a data line pair, a sense amplifier and an output unit. The plurality of memory cells are disposed adjacent to each other in a line. The data line pair is coupled to the memory cells to sequentially transfer memory data bits stored in the memory cells to the sense amplifier. The sense amplifier is configured to amplify the memory data bits that are sequentially transferred through the data line pair by corresponding delay times which are different from each other. The output unit samples an output of the sense amplifier to sequentially output retimed data bits of the memory data bits in response to a read clock signal. The read clock signal has a cyclic period which is less than a maximum delay time among the delay times.