A holster for a handgun, wherein the handguns includes a frame, a slide, and a hammer, the holster comprising: a holster body defining a cavity for receiving and holding a handgun; a pivot guard pivotably coupled to the body, wherein the pivot guard is pivotable between a closed position for securing a handgun within the cavity and an open position for insertion or removal of the handgun, wherein the pivot guard is biased to the open position by a pivot guard biasing means, wherein the pivot guard includes a pivot guard locking means for receiving at least a portion of a pivot guard locking portion of a pivot guard release lever for securing the pivot guard in the closed position; and a pivot guard release lever coupled to the holster body for releasably securing the pivot guard in the closed position, wherein the pivot guard release lever includes at least some of a pivot guard locking portion and a thumb/finger engagement portion, wherein the pivot guard release lever is biased to a pivot guard retention position such that the pivot guard locking portion protrudes into the pivot guard locking means so as to secure the pivot guard in the closed position, but wherein the pivot guard release lever is capable of being pivoted to a pivot guard release position when a pivoting force is applied to the thumb/finger engagement portion such that the pivot guard locking portion is sufficiently withdrawn from the pivot guard locking means so as to allow the pivot guard to pivot to the open position; characterized in that: the pivot guard includes a locking extension that extends from each side of the pivot guard and the holster body includes a corresponding retaining channels formed within the cavity such that when the pivot guard is in the closed position, each locking extension of the pivot guard extends into a corresponding retaining channel of the holster body; and said pivot guard locking portion protrudes through an aperture in the holster body in said pivot guard retention position. a holster body defining a cavity for receiving and holding a handgun; a pivot guard pivotably coupled to the body, wherein the pivot guard is pivotable between a closed position for securing a handgun within the cavity and an open position for insertion or removal of the handgun, wherein the pivot guard is biased to the open position by a pivot guard biasing means, wherein the pivot guard includes a pivot guard locking means for receiving at least a portion of a pivot guard locking portion of a pivot guard release lever for securing the pivot guard in the closed position; and a pivot guard release lever coupled to the holster body for releasably securing the pivot guard in the closed position, wherein the pivot guard release lever includes at least some of a pivot guard locking portion and a thumb/finger engagement portion, wherein the pivot guard release lever is biased to a pivot guard retention position such that the pivot guard locking portion protrudes into the pivot guard locking means so as to secure the pivot guard in the closed position, but wherein the pivot guard release lever is capable of being pivoted to a pivot guard release position when a pivoting force is applied to the thumb/finger engagement portion such that the pivot guard locking portion is sufficiently withdrawn from the pivot guard locking means so as to allow the pivot guard to pivot to the open position; the pivot guard includes a locking extension that extends from each side of the pivot guard and the holster body includes a corresponding retaining channels formed within the cavity such that when the pivot guard is in the closed position, each locking extension of the pivot guard extends into a corresponding retaining channel of the holster body; and said pivot guard locking portion protrudes through an aperture in the holster body in said pivot guard retention position.