The present invention provides a connector assembly having a small size and preventing a contact between a bolt fastener and a detection member. The connector assembly includes a connector having an inner chamber with an opening and a plurality of connector terminals, a connector receptacle having a plurality of connector receptacle terminals securable together with the connector terminals and a first detection member, and a cover for covering the opening and having a second detection member. When the opening of the inner chamber is covered with the cover, the first detection member and the second detection member are connected together and detect that the cover is covered. The first detection member is disposed between the adjacent connector receptacle terminals. An end surface of the first housing is positioned inwardly of the inner chamber with respect to a surface of a connector electrical contact portion.