How to Cite an Encyclopedia or Wikipedia Article in Chicago 18th edition (notes and bibliography)

Britannica, the Stanford Encyclopedia of Philosophy and other encyclopedias.

Example in Chicago 18th edition (notes and bibliography)

Ismael, Jenann. “Quantum Mechanics.” In The Stanford Encyclopedia of Philosophy, Spring 2025, edited by Edward N. Zalta and Uri Nodelman. Metaphysics Research Lab, Stanford University, 2025. https://plato.stanford.edu/archives/spr2025/entries/qm/.
Footnote Jenann Ismael, “Quantum Mechanics,” in The Stanford Encyclopedia of Philosophy, Spring 2025, ed. Edward N. Zalta and Uri Nodelman (Metaphysics Research Lab, Stanford University, 2025), https://plato.stanford.edu/archives/spr2025/entries/qm/.

Citing Wikipedia? Use this type, with the permanent link and the date of the version you read. We cite a Wikipedia article in the notes only. Chicago’s own example also lists it in the bibliography, under Wikimedia Foundation. How to cite Wikipedia

What Chicago 18th edition (notes and bibliography) includes

These are the details of the example above that the style prints, so they are the ones to collect for your own source.

  • Entry Title
  • Author(s)
  • Encyclopedia
  • Editor(s)
  • Edition
  • Publisher
  • Date Published
  • URL

Take the entry’s title, and its author if it names one, from the article, and the editors, edition and publisher from the encyclopedia’s title page or about page. Online, link to a fixed version if there is one, such as a Wikipedia permanent link or an archived edition of the Stanford Encyclopedia of Philosophy, and give its date. There is no box for a volume, so add one by hand if your style asks for it.

The formatting comes from the style's own file, so check the finer points against your guide. What to check by hand in Chicago 18th edition (notes and bibliography).

An Encyclopedia or Wikipedia Article in other styles

APA 7th edition MLA 9th edition Harvard (Cite Them Right 12th edition) IEEE Vancouver

Other sources in Chicago 18th edition (notes and bibliography)

Website Book Journal Article Newspaper Article Book Chapter Thesis/Dissertation Report Video Podcast/Broadcast Magazine Article Software Dataset Patent Legal Case Legislation Bill Regulation Hearing Standard Treaty Conference Paper Manuscript Review Book Review Classic Work Reference Entry Dictionary Entry Periodical Collection Interview Speech Song Musical Score Graphic Figure Map Performance Event Pamphlet Preprint Document Post Blog Post Personal Communication Generative AI