can refer to:
- Telephone jack - A connection system for telephone equipment. See Telephone plug.
- TRS connector (or jack plug, audio jack, stereo jack etc.) - An audio connector. ("Phone jack" is a US term - TRS connectors were used on telephone switchboards).
- Phone jack is sometimes confused with phono jack, an alternative name for RCA connectors. (The name "phono jack" is derived from their use on phonographs).