A miniature jack is a particularly small part of a plug connection that can accommodate matching plugs and thus establish electrical connections. Miniature jacks are often only a few millimetres in size and are therefore suitable for use on printed circuit boards as well as in applications, in which maintaining a certain size while maintaining reliability can be problematic. They are also used for stacking printed circuit boards on top of each other and for installing equipment within the chassis and control panels.

Typically, a miniature jack is connected to the circuit by soldering. To put the miniature jacks in their place, some models can be screwed in by using a thread. These also have a contact spring for shielding. Thanks to their simple design, miniature jacks have a long service life.