A firearm grip sleeve with retention feature has a body including a central bore and a meeting element. The mating element is connected to a mating feature on the frame of a firearm. The mating element is connected to a mating feature on the frame of a firearm. The mating element prevents undesirable movement of the body with respect to the firearm while the mating feature is connected to the mating element. The mating element may prevent axial movement and upward longitudinal movement of the body. The firearm may include a removable back strap insert.