The present invention is directed to connectors for lighting strips. More particularly, the present invention relates to modular lighting systems, which provide for physical and electrical interconnection of multiple lighting strip devices to form lighting systems. In an embodiment, the present invention provides a connector assembly for modular lighting strips comprising: two or more integrally-formed plugs or sockets joined together in a manner to provide for physical and electrical connection with two or more lighting strips comprising a non-conductive substrate strip with an electrical circuit; a plurality of light sources operably connected to the electrical circuit; and a plug or socket integrally formed at opposing ends of the substrate strip; wherein the plugs and sockets provide for removable, friction-fit, and electrical interconnection of two or more circuits of the lighting strips.