Abstract: The present invention relates to a trigger lock that is attachable to the trigger of firearms to prevent accidental discharge. The trigger lock comprises a pair of spaced apart pins that are attached to and extend normally from a plate, the pins being sized and configured to be received by axial apertures within a pair of cylinders that are attached in spaced apart relation and generally normal to the first side of a base. A pair of second apertures extend from the second side of the base to intersect respective first apertures. The second apertures have a larger circumference than the first apertures to define a ledge at each intersection. A nub is attached to at least one pin proximal to the free end of that pin and the nub is releasably engageable with the ledge within the cylinder locking the pins in the cylinders.