A roller sear/hammer interface for a firearm. The sear has a roller rotatably mounted between two side plates forming a portion of the sear body. As the trigger is moved, a linkage connecting the trigger and sear causes the sear to pivot rearward such that the roller engages a notched surface formed in the hammer. This rolling action releases the hammer to strike a firing pin to fire a round of ammunition. When the trigger is released, the sear roller rolls downward into an engaged and locked position within the notch formed in the hammer.