An apparatus and method for transmitting and receiving wireless packet data are provided. In a wireless packet data transmitter for transmitting to a wireless packet data receiver data packet on a transport channel and control information for supporting the transport channel on a control channel in a wireless packet data communications system, a padding bit eliminator eliminates optional padding bits of a variable size from a transport block for data packet transmission. A transport channel encoder for transport channel-encodes the transport block without the padding bits and transmits the encoded transport block on the transport channel. A control channel encoder control channel-encodes the control information including a padding bit number indicator indicating the number of the eliminated padding bits and transmits the encoded control information on the control channel.