Disclosed is a method for transmitting, by a terminal supporting a sidelink, a sidelink synchronization signal block (S-SSB) in a wireless communication system. Specifically, the present disclosure comprises transmitting, from a specific slot, an S-SSB including a primary sidelink synchronization signal (PSSS), a secondary sidelink synchronization signal (SSSS), and a physical sidelink broadcast channel (PSBCH), wherein the PSBCH is mapped to first orthogonal frequency division multiplexing (OFDM) symbols included in the specific slot, and the first OFDM symbols are located after second OFDM symbols for the SSSS.