A keychain is a small ring, chain, or holder used to keep your keys together in one place. Most keychains are metal rings that you pry open to add or remove keys, though some use chains or clips instead. By keeping all your keys on a single keychain, you avoid losing them individually and can find them quickly when you need to unlock your house, your bike lock, or anything else.

People often attach small decorative objects called key fobs or charms to their keychains. These might be miniature toys, photos in plastic cases, or meaningful souvenirs from trips. Some keychains include practical additions like tiny flashlights, bottle openers, or whistles. The decorations serve a purpose beyond looks: a bulky or distinctive keychain is harder to misplace than a single key, and the extra weight makes it easier to feel in your pocket or hear when it drops.

The word can also refer to the entire collection of keys and attachments hanging together. When someone says “I can't find my keychain,” they mean the whole bundle, not just the ring itself.