How to cite a Wikipedia article (APA 7, MLA 9, Chicago, Harvard)

When to use this format

Use this format when you genuinely cite a Wikipedia article, for example when the encyclopedia entry itself is your subject, when you are illustrating how a topic is summarised, or when an instructor permits it for background. Because the page is collaboratively edited and undated at the top, you must cite a specific stored revision so a reader sees exactly what you saw.

Before citing Wikipedia at all, check whether it is the right source. For most academic claims, Wikipedia is a starting point, not an authority, and the better move is to follow its reference list to the primary or scholarly source and cite that instead. Many courses do not accept Wikipedia as evidence, so treat it as a finding aid unless the article itself is what you are studying.

What you need before you start

Collect these details from the Wikipedia article itself, not from a search result or a reposted copy. Getting the fields right once makes every style format below fall into place.

• Article title, used as the title with Wikipedia as the source.
• The date of the specific revision you read.
• Wikipedia, The Free Encyclopedia, as the publisher or site.
• The permanent link from View history, not the live article URL.
• An access date where the style requires it.
• No individual author, because contributions are collective.

Worked examples in four styles

The same facts appear in every style, but they move around and change punctuation. Match the reference-list entry and the in-text citation to the style your assignment requires.

Photosynthesis. (2026, January 3). In Wikipedia. https://en.wikipedia.org/w/index.php?title=Photosynthesis&oldid=1234567890

"Photosynthesis." Wikipedia, Wikimedia Foundation, 3 Jan. 2026, en.wikipedia.org/w/index.php?title=Photosynthesis&oldid=1234567890.

Wikipedia. 2026. “Photosynthesis.” Last modified January 3, 2026. https://en.wikipedia.org/w/index.php?title=Photosynthesis&oldid=1234567890.

Wikipedia (2026) Photosynthesis. Available at: https://en.wikipedia.org/w/index.php?title=Photosynthesis&oldid=1234567890 (Accessed: 15 January 2026).

Judgement calls and edge cases

The permanent link is the single most important detail. From any article, open View history, click the timestamp of the version you read, and copy that URL; it contains an oldid parameter that freezes the article at that revision. A live link points at whatever the article says now, which may contradict what you quoted, so the permanent link is what turns a moving target into a citable source.

Wikipedia has no individual author, so do not invent one. Contributions are collective and anonymous, which is why every style starts the entry with the article title and names Wikipedia or the Wikimedia Foundation as the publisher. Crediting a username you saw in the history is wrong, because that person did not write the whole article and the page is not attributed to them.

Most of the time the smarter citation is the one Wikipedia itself points to. The value of a Wikipedia article is often its reference list, which leads to peer-reviewed papers, official statistics, and primary documents. For a claim that needs authority, follow the footnote to the original source and cite that, and reserve a direct Wikipedia citation for cases where the encyclopedia entry is genuinely your subject.

Common mistakes

• Citing the live article URL instead of the dated permanent link.
• Inventing an author from the edit history.
• Omitting the revision date, which leaves the version unidentifiable.
• Citing Wikipedia for a claim that needs a primary or scholarly source.
• Using Wikipedia where the course explicitly forbids it as evidence.