A firearm holster comprising a primary safety mechanism and secondary safety mechanism to secure a firearm within a holster. The primary safety mechanism includes a pivotal triggering lever coupled to a resettable drop lock via a slider assembly. The resettable drop lock engages an ejection port of a firearm and is released by depressing the pivotal triggering lever that activates a slider assembly. The secondary safety mechanism includes a trigger operatively coupled to a canopy disposed on a rear portion of the firearm holster. The canopy is activated by pushing the thumb lever in a sideways direction which causes the canopy to rotate and open. For quick-release use, the pivotal triggering lever and the trigger may be positioned in proximity to each other such that a user’s thumb can activate both the pivotal triggering lever and the trigger in one fluid motion.