Flintlock is a general term for any firearm that uses a flint-striking ignition mechanism, the first of which appeared in Western Europe in the early 16th century. The term may also apply to a particular form of the mechanism itself, also known as the true flintlock, that was introduced in the early 17th century, and gradually replaced earlier firearm-ignition technologies, such as the matchlock, the wheellock, and the earlier flintlock mechanisms such as snaplock and snaphaunce.

The true flintlock continued to be in common use for over two centuries, replaced by percussion cap and, later, the cartridge-based systems in the early-to-mid 19th century. Although long superseded by modern firearms, flintlock weapons enjoy continuing popularity with black-powder shooting enthusiasts.