Abstract: A slide cover plate adapter and related methods of use for adding functionality to a semi-automatic handgun. The slide cover plate adapter replaces a factory slide cover plate located at a rear wall of a slide assembly in conventional semi-automatic handguns. The slide cover plate adapter includes a channel engagement portion and an accessory engagement portion that are spaced apart and coupled with a bridging member. The channel engagement portion operably couples to the slide assembly while the accessory engagement portion provides a convenient attachment point for any of a variety of handgun accessories.