A firearm grip assembly includes a firearm adapter having functionality for engaging the receiver of a firearm. An elongated handgrip body having an opening along the top end slidingly receives the bottom end of the adapter. The latching mechanism is positioned within the adapter and includes a resilient member having a pair of buttons extending outward therefrom. The buttons are positioned through a first set of openings located on the adapter body and are selectively positioned within a second pair of openings on the handgrip body when the adapter is positioned within the handgrip body.