A connector (10) includes a housing (12) having an opening (24) open rearward. A seal ring (28) prevents water from entering the housing (12) from the side of the opening (24) by being inserted into the opening (24) and resiliently contacting an inner peripheral surface (29) of the opening (24). A retainer (16) has a contact portion (86) configured to contact the seal ring (28) from behind. The retainer (16) is configured to hold the seal ring (28) in the housing (12) by having the contact portion (86) contact the seal ring (28). The retainer (16) is mounted on the housing (12) to cover the opening (24) of the housing (12). A first drainage port (80) is open in an inner wall of the retainer (16) and is configured so that water that has entered the retainer (16) and adhered to the seal ring (28) is discharged to outside.