The invention provides a nozzle for a pressure vessel and a pressure vessel. The pressure vessel for storing high-pressure gas has a structure including: a nozzle body which is coupled to a vessel body that defines an inner wall surface of the pressure vessel, and has an inner flow path through which gas flows inside and outside of the pressure vessel; and a locker which is fastened to a lower portion of the nozzle body, and the structure is configured to provide dual sealing including sealing at an inclined surface by fastening force of the locker generated by an inclined pressing end of the locker, and sealing in the locker by sealing members.