---
name: citation-style-chicago
description: Use when asked to cite sources, format in-text citations, or build a reference list in Chicago Manual of Style citation, in both of its systems, used in history, the arts, the humanities (notes-bibliography), and the sciences and social sciences (author-date); a style with two systems, unlike the single-system [[citation-style-apa]] and [[citation-style-mla]].
---

# Chicago Citation Style

Chicago Manual of Style citation, in both of its systems is the style commonly required in history, the arts, the humanities (notes-bibliography), and the sciences and social sciences (author-date). Family: Two systems: notes-bibliography, and author-date.

## Input required

- The sources to cite, with author, title, date, publisher or journal, volume, issue, pages, and DOI or URL.
- The edition, institution, or journal whose rules apply.

## Questions to ask first

1. Which edition or institutional variant must the work follow?
2. Is the output in-text citations, reference-list entries, or both?
3. What type is each source (book, article, web page, report, legal authority)?
4. Is any information missing, such as the date, pages, or DOI?

## In-text citations

- **Notes-bibliography:** a superscript number in the text points to a footnote or endnote. The first note for a source is full; later notes are shortened (author, short title, page).
- **Author-date:** parenthetical `(Smith 2020, 45)`, with no comma between author and year.
- Ask the user which system, and which edition (17th or 18th) their course or publisher requires, before formatting.

## Reference format

Notes-bibliography ends with a `Bibliography`; author-date ends with a `References` list. Both are alphabetical with a hanging indent and use headline-style (title case) capitalization. In the bibliography, the author's name is inverted and elements are separated by periods; in notes, the name is not inverted and elements are separated by commas.

## Example pattern

The names, title, and numbers below are placeholders showing the pattern, not a real source.

```text
Note: 1. Jane A. Smith and Kim Lee, "Title of the Article," *Journal Name* 12, no. 3 (2020): 47.
Bibliography: Smith, Jane A., and Kim Lee. "Title of the Article." *Journal Name* 12, no. 3 (2020): 45–67.
```

## Ground rules

- Use only the details the user supplied or that can be checked. Never invent authors, dates, DOIs, page numbers, or sources.
- If a detail is missing, leave a clear placeholder and say so.
- Apply one style consistently throughout the document.
- When the user's institution or journal differs from this guide, follow theirs.

## Self-check before answering

- Does every in-text citation have a matching reference entry, and the reverse?
- Are the ordering, capitalization, punctuation, and italics consistent with this style?
- Were any details guessed? Remove or flag them.

## Common pitfalls

- **Mixing the two systems** — pick one and use it throughout.
- **Using the bibliography format in a note** — a note uses commas and an uninverted name; a bibliography entry uses periods and an inverted first author.
- **Repeating the full note every time** — shorten later notes; use a short title, not `ibid.`, unless the user's guide permits it.
- **Page range in a note** — a note cites the specific page used, while the bibliography gives the whole range.

## Learn more

- Compare with the other styles: [[citation-style-apa]], [[citation-style-mla]], [[citation-style-harvard]], [[citation-style-vancouver]], [[citation-style-ieee]], [[citation-style-ama]], [[citation-style-oscola]].
- Official guidance: [The Chicago Manual of Style Online](https://www.chicagomanualofstyle.org/).