A framelock (also frame lock) is a special type of locking mechanism used in one-handed knives. Knives equipped with this mechanism are called framelock knives. The framelock closure system makes it possible to open and close a knife with one hand.

The main components of a frame lockknife are the riveted handle scales and the blade. One of the handle scales of a framelock knife has an L-shaped notch at the bottom that begins just below the front of the handle scale and runs across approximately two thirds of the handle length. The scale section partly separated by the notch is curved slightly inward.

The locking mechanism of a framelock works as follows: While the blade is closed, it is held back by the partly separated section of the handle scale, which exerts inward pressure. When the blade is opened, this part of the handle scale moves inward, locking the blade. Unlike the linerlock, which has a separate locking plate covered by the handle scales, the framelock is part of the handle itself.

The name of this locking mechanism is derived from its construction, because it is the frame that creates the lock. The handle scales of a framelock knife are usually made from particularly hard metals such as titanium or stainless steel, because these materials offer adequate resistance to the blade when the knife is used.