The Term Snaphance or Snaphaunce refers to a mechanism for igniting a firearm's propellant in a muzzle loading gun. The mechanism, which first appeared in the late 1550s, uses flint and steel to create a shower of sparks to ignite the propellant in the gun.

The flint is held in a clamp at the end of a bent lever called the cock. Upon pulling the trigger, this moves forward under the pressure of a strong spring and strikes a curved plate of hardened steel - called simply the steel, or in 17th century English dialect the frizzen - producing a shower of sparks (actually white hot steel shavings). These fall into a flash pan holding priming powder. The flash from the pan travels through the touch hole causing the main charge of gunpowder to deflagrate.

The snaphance was a development of the earlier snaplock mechanism, the main difference being the Snaphance used an automatic pan-cover (to keep the priming dry until the exact moment of firing) similar to that used in the wheel-lock, whereas the Snaplock had a manually operated pan cover similar to that of the matchlock. The Snaphance also used the lateral sear mechanism from the wheel-lock to connect trigger to cock, and later, improved models also had a variety of safety mechanisms to prevent accidental discharge of the gun.

The Snaphance was used from the late 1550s until modern times (in North African guns), but by about 1680 it was out of fashion everywhere except Northern Italy where it persisted until the 1750s. In Europe, and especially France, the Snaphance was replaced by the flintlock with its combined steel/pan cover starting from about 1620. In England, a hybrid mechanism called the English Lock replaced the Snaphance from the same date. Both the flintlock and the English lock were cheaper and less complex than the Snaphance.

The origin of the name Snaphance is thought to come from the Dutch language "Snap Haan" or German language "Schnapphahn" and has two attributions. The first is that the action of the mechanism was likened to a chicken pecking at grain (thus the name "cock" for part of the mechanism). The second attributes the use of this type of gun to chicken thieves, who would be given away by the sight and smell of a burning match if they had used the earlier matchlock gun, instead of a Snaphance in their nocturnal depredations. The German word Schnapphahn had however since moved away from the earlier definitions and has traditionally referred to a mounted highwayman, who would have been likely to use a firearm of that nature.