A watertight connector has a one-piece rubber plug (50) on a rear part of a housing (70), and a rear holder (30) to be locked to the housing (70) is behind the rubber plug (50). A receptacle 10 is fit externally to the housing (70) from the front and closely contacts lips (55) of the rubber plug (50). The receptacle (10) includes short side walls (15) facing each other in a first direction and long side walls (14) facing each other in a second direction. The rear holder (30) includes short surfaces (38) at inner sides of the short side walls (15) and long surfaces (37) at inner sides of the long side walls (14). Holder-side escaping portions (43) retracted more backward than front ends of the long surfaces (37) are provided on front ends of the short surfaces (38) of the rear holder (30).