A ROM cartridge, sometimes referred to as a cart, is a removable enclosure containing read-only memory devices designed to be connected to a computer or games console.

ROM cartridges can be used to add additional functionality or content to the host machine, hardware additions like speech synthesis, or software such as video games.

ROM cartridges were popularized by early home computers which featured a special bus port for the insertion of cartridges containing software in ROM. In most cases the designs were fairly crude, with the entire address and data buses exposed by the port and attached via an edge connector; the cartridge was memory mapped directly into the system's address space.

Notable computers using cartridges in addition to magnetic media were the Commodore VIC-20 and 64, the Atari 8-bit family (400/800/XL/XE), the Texas Instruments TI-99/4A (where they were called Solid State Command Modules and were not directly mapped to the system bus) and the IBM PCjr (where the cartridge was mapped into BIOS space).