Loader can refer to:

Loader (equipment)
Loader (computing)
LOADER.EXE, an auto-start program loader optionally used in the startup process of Microsoft Windows ME
Loader (surname)
Fast loader
Speedloader
Boot loader
LOADER.COM (aka "NEWLDR"), a multi-boot loader shipping with various Digital Research, Novell, IMS, Caldera, etc. DOS-based operating systems like Multiuser DOS and DR-DOS
LOADER.SYS, part of a LOADER.COM installation (see above)
Clapper loader (on a film crew, also simply known as "loader")
A loader, a member of a crew responsible for handling and loading ammunition, such as on a howitzer or tank crew
Autoloader, an automated replacement for a crewer loader