A terminal assembly includes a wire including a core made of metal and covered with a coating, a terminal including a wire connecting portion connected to an end portion of the wire, a sealing resin sealing the wire connecting portion, and a housing including a through hole with a front opening and a rear opening. The terminal is made of a different kind of metal from the core of the wire. The housing accommodates the terminal in the through hole. The wire connecting portion includes an exposed portion not covered with the sealing resin and unexposed portions covered with the sealing resin. The exposed portion is positioned between the unexposed portions in a front and rear direction, thereby protecting the wire connecting portion from electrolytic corrosion. The exposed portion is obtained after the sealing resin is worn by being rubbed against an inner wall of the through hole.