A folding bicycle is a type of bicycles which can fold and unfold (most bicycles fold once).

They are popular in the Orient and the United Kingdom, less so in the United States.

Common types include the Brompton bicycle (British), the Dahon bicycle (Made in Taiwan, although headquartered in California), the Bike Friday (American), and the Airnimal (Great Britain).

The wide variety of folding bicycles reflects different ideas about what a folding bicycle should be. The Brompton, for example, is optimized for sturdiness, quick deployment, and small size. The Airnimal, by contrast, is designed for cyclists who wish to pack it convieniently; it takes a long time to fold and unfold, but is very like a regular bike in uses.