钥匙圈又称钥匙扣、锁匙扣，是一个用来扣住钥匙和其他东西的环（一般材质是金属或者塑胶），有时候会与钥匙链（key chain）连在一起。有的钥匙圈是用皮革，木头，或者橡胶做成的。

最常见的钥匙圈是一片头尾有重叠的金属环。两端都可以撬开来让钥匙能滑入环中，直到钥匙完全进入环的内部。另外也有的钥匙圈会加上很多装饰物来作为辨识，这些有装饰物的钥匙圈也常会被人挂在袋子上作为装饰。

有的钥匙圈会使用没有重叠部份的金属或塑胶环，但是利用其它机制（像是卡榫之类）来让这个环可以适当地打开与关闭。

A keychain or key chain is a small chain, usually made from metal or plastic, that connects a small item to a keyring. The length of a keychain allows an item to be used more easily than if connected directly to a keyring. Some keychains allow one or both ends the ability to rotate, keeping the keychain from becoming twisted, while the item is being used. A keychain can also be a connecting link between a keyring and the belt of an individual. It is usually employed by personnel whose job demands frequent use of keys, such as a security guard, prison officer, janitor, or retail store manager. The chain is often retractable, and therefore may be a nylon rope, instead of an actual metal chain. The chain ensures that the keys remain attached to the individual using them, makes accidental loss less likely, and saves on wear and tear on the pockets of the user.