Folder may refer:
- File folder, a kind of folder that holds loose paper.
- Folder (computing), a virtual container within a digital file system, in which groups of files and other folders can be kept and organized
- Folding machine, a machine used for folding paper
- Folding bicycle, a bicycle which can be folded for compactness
- Folder 5, a J-pop group formerly called Folder
- Pole Folder, a producer of electronic music
- Short Folder, a series of aeroplanes designed with folding wings for shipborne use (from 1913)