Disclosed are a method and apparatus for transmitting/receiving a broadcast signal including a robust header compression (RoHC) packet stream and fast information. The method for transmitting a broadcast signal includes encoding broadcast data, generating a packet including the encoded broadcast data, generating a robust header compression (RoHC) packet by performing RoHC on a header of the generated packet, generating fast information including configuration information of a broadcast stream and broadcast service related information and transmitting the fast information through a second channel, and transmitting the broadcast stream including the generated RoHC packet through a second channel.