A columnist is a journalist who writes for publication in a series, creating copy that can sometimes be strongly opinionated. Columns appear in newspapers, magazines and other publications, including blogs on the Internet.

Readers often open a publication with an expectation of reading a new essay by a specific writer who offers a personal point of view. In some instances, a column has been written by a composite or a team, appearing under a pseudonym, or in effect, a brand name.

Some columnists appear on a daily basis and later reprint the same material in book collections. Notable contemporary columnists include David Aaronovitch, Nick Cohen, Gail Collins, Ann Coulter, Ardeshir Cowasjee, E. J. Dionne, Maureen Dowd, Gwynne Dyer, Thomas Friedman, Ellen Goodman, Bob Herbert, David Ignatius, Molly Ivins, Charles Krauthammer, Nicholas D. Kristof, Paul Krugman, Johann Hari, Christopher Hitchens, Al Lewis, Clarence Page, Chandrakant Lahariya, Rick Reilly, Frank Rich and Mike Royko.

In defining a column, Dictionary.com provides a breakdown of a few popular subjects covered by columnists:

A regular feature or series of articles in a newspaper, magazine, or the like, usually having a readily identifiable heading and the byline of the writer or editor, that reports or comments upon a particular field of interest, as politics, theater, or etiquette, or which may contain letters from readers, answers to readers' queries, etc.