An interleaving method and apparatus for adaptively determining an interleaving depth of each of one or more interleaving blocks based on a maximum interleaving depth and a number of codewords of a packet, and interleaving the interleaving blocks based on the interleaving depth. The adaptively determining the interleaving depth includes: calculating a number of remaining codewords by performing a modulo operation on a basic interleaving depth and the number of the codewords; and determining the interleaving depth by adjusting the basic interleaving depth based on the number of the remaining codewords.