A decoding circuit and method for improving error correction capability using a stuffing byte, in which in the decoding method, an input data packet is decoded. When it is determined that error correction is impossible based on a decoding result, a stuffing byte section is detected in the input data packet. A level value of data in the stuffing byte section is converted into a stuffing byte level value. A data packet having the converted level value is decoded and output. The decoding circuit includes a decoder decoding an input data packet and a control block detecting a stuffing byte section in the input data packet, converting the input data packet, and decoding a converted data packet when the decoder fails in error correction of the input data packet.