A TRS connector (tip, ring, sleeve) is a common family of connector typically used for analog signals including audio. It is cylindrical in shape, typically with three contacts, although sometimes with two (a TS connector) or four (a TRRS connector).

It is also termed an audio jack, phone jack, phone plug, and jack plug. Specific models are termed stereo plug, mini-jack, mini-stereo, headphone jack, tiny telephone connector and bantam plug.

The TRS connector was invented for use in telephone switchboards in the 20th century and is still widely used, both in its original 1⁄4 in (exactly 6.35 mm) size and in miniaturized versions: 3.5 mm (approx. 1⁄8 in) and 2.5 mm (approx. 3⁄32 in). The connector's name is an initialism derived from the names of three conducting parts of the plug: Tip, Ring, and Sleeve — hence, TRS.

These examples are meant to illustrate each possible component of such jacks, but many other configurations using these basic components are available. All examples in the above figure are oriented so the plug 'enters' from the right.

A. A simple two-conductor jack. The connection to the sleeve is the rectangle towards the right, and the connection to the tip is the line with the notch. Wiring connections are illustrated as white circles.

B. A three-conductor, or TRS, jack. The upper connector is the tip, as it is farther away from the sleeve. The sleeve is shown connected directly to the chassis, a very common configuration. This is the typical configuration for a balanced connection. Some jacks have metal mounting connections (which would make this connection) and some have plastic, to isolate the sleeve from the chassis, and provide a separate sleeve connection point, as in A.

C. This three-conductor jack has two isolated SPDT switches. They are activated by a plug going into the jack, which disconnects one throw and connects the other. The white arrowheads indicate a mechanical connection, while the black arrowheads indicate an electrical connection. This would be useful for a device that turns on when a plug is inserted, and off otherwise, with the power routed through the switches.

D. This three-conductor jack has two normally closed switches connected to the contacts themselves. This would be useful for a patch point, for instance, or for allowing another signal to feed the line until a plug is inserted. The switches open when a plug is inserted. A common use for this style of connector is a stereo headphone jack that shuts off the default output (speakers) when the connector is plugged in.

The most common circuit configurations are the simple mono and stereo jacks (A and B above), however there are a great number of variants manufactured.