An interleaving apparatus may include a first buffer unit configured to buffer input data in units having a size of a sector to generate sector unit data, an encoding unit configured to encode the sector unit data and generate a plurality of parity codes based on the encoding, a second buffer unit configured to interleave the sector unit data and the parity codes and generate interleaving data based on the interleaving, the second buffer unit including a plurality of output buffers configured to store the interleaving data, and an output unit configured to output the interleaving data.