The present disclosure relates to a low-complexity syndrome based decoding apparatus and method and a low-complexity syndrome based decoding apparatus includes: a hard decision unit which performs hard decision on a current input value to output a hard decision vector; a syndrome calculator which performs a syndrome operation on the hard decision vector and determines an error type of the hard decision vector based on the syndrome operation result; and a decoder which selects a predetermined decoding algorithm in accordance with the error type to perform the decoding, and the error type includes at least one of no error, a single error, and a double error.