A commentator is an individual who comments on sports, politics, current events, or public issues; synonyms include pundit. Social commentator may cover anything from a preacher to a columnist to a cultural critic.

A live broadcast of a major public event, such as inauguration, funeral of a public figure, space flight or sporting occasion, is almost invariably accompanied by the thoughts of a commentator. This may be on television, accompanied by relevant images, or on radio. The technique involved differs between the two media, with radio broadcasters needing to be more explicit and descriptive because of the absence of pictures.

Sports and other commentators usually broadcast live during events, in an essentially unscripted way, though they may refer to prepared materials, for example on sports statistics. Spontaneity, and even enthusiasm and partisan comments, are sometimes valued by those watching or listening to sports.

Gaffes and other verbal mishaps can occur. Famous examples include:

• "'For those of you watching in black and white, the blue is behind the pink" – snooker commentator Ted Lowe
• "If history repeats itself, I should think we can expect the same thing again." Football manager Terry Venables
• "One of the reasons Arnold Palmer is playing so well is that, before each tee shot, his wife takes out his balls and kisses them.... Oh my God, what have I just said?" – USTV golf commentator Sandi

Some famous commentators include:

• Yogi Berra
• Howard Cosell
• Paul Harvey
• Rush Limbaugh
• John Madden
• Michael Savage
• Murray Walker