A connector housing includes a housing body, a sealing member interposed between an outer circumferential surface of the housing body and an inner circumferential surface of a mating housing body to seal a space between the outer circumferential surface and the inner circumferential surface, a restriction wall portion standing on the outer circumferential surface of the housing body and positioned on a side of the rear opening with respect to a position of the sealing member, and a restriction flexible piece formed on a circumferential wall of the housing body and formed in a cantilever beam shape, the restriction flexible piece being configured such that a projection of a free end thereof is pushed up by a connector terminal so the free end protrudes from the outer circumferential surface, and the free end restricts movement of the sealing member toward the side of the connection side opening.