隐藏字幕（Closed Captioning，简称CC）是电视节目或影碟中为有特殊情况或者需要的观众而准备的字幕，例如观众在听力上有障碍，或者需要无音条件下观赏节目。此时字幕中可使用一些解释性的语言来描述节目内容。这种字幕常见于DVD-Video与蓝光光盘。如果电视节目或影碟有提供隐藏字幕，只要按一下相关按钮，即可开启字幕。在模拟电视技术中，隐藏字幕透过阴极射线管在显示画面时出现的垂直空白间隙（Vertical Blank Interval, VBI）来实现。

Closed captioning (CC) and subtitling are both processes of displaying text on a television, video screen, or other visual display to provide additional or interpretive information. Both are typically used as a transcription of the audio portion of a program as it occurs (either verbatim or in edited form), sometimes including descriptions of non-speech elements. Other uses have been to provide a textual alternative language translation of a presentation's primary audio language that is usually burned-in (or "open") to the video and unselectable. HTML5 defines subtitles as a "transcription or translation of the dialogue ... when sound is available but not understood" by the viewer (for example, dialogue in a foreign language) and captions as a "transcription or translation of the dialogue, sound effects, relevant musical cues, and other relevant audio information ... when sound is unavailable or not clearly audible" (for example, when audio is muted or the viewer is deaf or hard of hearing).