Chicago / Turabian Referencing: A Complete Guide with Examples (2026)

Chicago style: two systems, one manual

Chicago is the most flexible of the major styles, because The Chicago Manual of Style documents two distinct systems and lets the discipline choose. The notes–bibliography system is standard in history, art history, theology, philosophy and much of the humanities: you place a superscript number in the text and give the citation in a footnote (bottom of the page) or endnote (end of the document), with a full bibliography at the end. The author–date system is used in the sciences, social sciences and increasingly in business: you cite (Author year) in the text and give a reference list, very much like Harvard or APA.

Most students who are asked for ‘Chicago’ in the humanities mean notes–bibliography, so this guide leads with that and explains author–date alongside. If you are an undergraduate, your tutor may refer to Turabian — Kate Turabian’s A Manual for Writers — which is the student edition of Chicago and follows the same rules in a more accessible form. The current Chicago manual is the 18th edition (2024); the long-standing 17th edition is still widely used, and the citation formats are essentially the same.

The first rule, as always, is to confirm which system your department wants. Citing in author–date when your tutor expects footnotes — or the reverse — is a fundamental error, however neat your individual entries are.

When and where you’ll use Chicago

Notes–bibliography Chicago is the default in history and is common across the humanities, especially in North America. Author–date Chicago appears in the natural and social sciences and in some business schools. Because Chicago footnotes can carry commentary as well as citations, historians value the system for letting them add nuance without cluttering the main text.

You will meet Chicago in essays, research papers, theses and book-length work. This guide concentrates on citation in both systems, which is where marks are won or lost.

Footnotes and author–date citations

Notes–bibliography. Put a superscript number at the end of the sentence, after the punctuation, and give the citation in a matching note. The first note for a source is full; later notes are shortened.

• First full note (book): 1. John Smith, Organisational Behaviour in Practice, 3rd ed. (London: Routledge, 2020), 23.
• Shortened note thereafter: 2. Smith, Organisational Behaviour, 25.
• First full note (journal): 3. Richard M. Ryan and Edward L. Deci, ‘Self-Determination Theory,’ American Psychologist 55, no. 1 (2000): 70.
• Consecutive note, same source: use the page only, or ‘Ibid., 26’ in the 17th edition (the 18th edition prefers a shortened note).

Author–date. Cite in brackets like Harvard: (Smith 2020, 23) — note the comma before the page and no ‘p.’. Two authors: (Smith and Jones 2020). Three or more: (Smith et al. 2020). Each in-text citation has a matching reference-list entry.

Bibliography and reference-list format

In notes–bibliography, the end list is headed Bibliography; in author–date it is headed References. Both are alphabetical by surname with a hanging indent. Crucially, the bibliography entry differs from the footnote: the bibliography inverts the first author’s name (Surname, First), uses full stops rather than commas between elements, and gives no page number for a whole book. The table below shows the bibliography (notes–bibliography) format for each common source type; the author–date reference entry is similar but moves the year next to the author.

A sample Chicago bibliography

Assembled, a notes–bibliography list looks like this:

Jones, Alice. ‘Leading Change.’ In Modern Management, edited by Rahul Patel, 45–62. Oxford: Oxford University Press, 2019.

Ryan, Richard M., and Edward L. Deci. ‘Self-Determination Theory.’ American Psychologist 55, no. 1 (2000): 68–78.

Smith, John. Organisational Behaviour in Practice. 3rd ed. London: Routledge, 2020.

Quoting, paraphrasing and using footnotes well

Chicago’s footnote system gives you a powerful tool: the note can hold both the citation and a short comment that would interrupt the main text — a qualification, a cross-reference, or a nod to a debate. Use this sparingly and purposefully; a footnote is not a place to hide material that belongs in the argument.

Direct quotations sit in quotation marks with a note number; quotations longer than about five lines (or 100 words) are set as an indented block quotation without quotation marks. Paraphrasing still takes a note (NB system) or an in-text citation (author–date), because the idea belongs to the source. As in every style, restating a point without crediting it is plagiarism, and changing only a few words is patchwriting. Historians in particular prize careful paraphrase and synthesis of primary and secondary sources over long quotation.

Step by step: a first footnote and its bibliography entry

The note and the bibliography entry for the same source differ, so build both:

1. Note — author in natural order: John Smith,
2. Title in italics, title case: Organisational Behaviour in Practice,
3. Edition + publication facts in brackets: 3rd ed. (London: Routledge, 2020),
4. Page cited: 23.

Full note: 1. John Smith, Organisational Behaviour in Practice, 3rd ed. (London: Routledge, 2020), 23.

Bibliography entry — invert the name, swap brackets for full stops, drop the single page: Smith, John. Organisational Behaviour in Practice. 3rd ed. London: Routledge, 2020.

Chicago formatting rules that lose easy marks

• Note vs bibliography form. Notes use commas and natural name order; bibliography entries use full stops and invert the first author’s name.
• Superscript number after punctuation. The note marker comes after the full stop or comma, not before.
• Shorten repeat notes. After the first full note, use Surname, short title, page.
• Title case for titles; italics for books and journals, quotation marks for articles and chapters.
• ‘Bibliography’ (NB) vs ‘References’ (author–date) — use the right heading for your system.

The six most common Chicago mistakes

1. Mixing the two systems. Footnotes belong to notes–bibliography; (Author year) belongs to author–date. Do not combine them.
2. Using note form in the bibliography. The bibliography inverts the name and uses full stops, not the comma-separated note format.
3. Never shortening repeat notes. Only the first note for a source is full; the rest are shortened.
4. Forgetting the comma and page rule in author–date. It is (Smith 2020, 23), with a comma and no ‘p.’.
5. Wrong heading. ‘Bibliography’ for NB, ‘References’ for author–date.
6. Inconsistent edition rules. Pick the 17th or 18th edition to match your course and apply it throughout.

How Chicago differs from Harvard, APA and MLA

Chicago is unusual in offering two systems. Its author–date form closely resembles Harvard and APA — (Author year) with a reference list — though the punctuation differs in details. Its notes–bibliography form is quite unlike the others: citations live in footnotes, not in brackets, which is why historians favour it. MLA, by contrast, is author–page and used in literary studies. If your modules span history and the social sciences you may need both Chicago systems; identify which one each assignment wants. Our citation styles comparison puts them side by side.

Footnotes, endnotes and where the bibliography goes

In the notes–bibliography system you can place your notes in one of two ways. Footnotes sit at the bottom of the page on which the citation appears; endnotes are gathered together on a ‘Notes’ page at the end of the document, before the bibliography. The content is identical — only the position changes — and most word processors insert and renumber them automatically, so choose whichever your department prefers and apply it consistently. Footnotes are easier for the reader, who can glance down rather than flip to the back.

The note number in the text is a superscript placed after the closing punctuation. Notes are numbered consecutively through the whole document. At the end, the Bibliography lists every source alphabetically by author surname, regardless of the order in which they appeared in the notes — so a reader can find a source either way: by following a note, or by scanning the bibliography. Keep the two in step: every source cited in a note should appear in the bibliography, and a healthy bibliography signals the depth of your research to an examiner before they read your argument.

Reference faster, without the errors

The authoritative source for Chicago

The definitive reference is The Chicago Manual of Style (18th edition, 2024; the 17th edition remains in wide use). For students, Kate Turabian’s A Manual for Writers of Research Papers, Theses, and Dissertations presents the same rules in a more approachable form. The free Chicago Manual of Style Online Citation Quick Guide is a reliable place to confirm a format.

Related referencing guides

• MLA 9th format & citation guide
• Harvard (Cite Them Right) referencing guide
• IEEE referencing for engineering
• Citation styles compared: Harvard vs APA vs MLA vs more

Frequently asked questions

What is the difference between Chicago’s two systems?

Notes–bibliography uses numbered footnotes or endnotes plus a bibliography, and is standard in history and the humanities. Author–date uses (Author year) in the text plus a reference list, like Harvard, and is used in the sciences and social sciences. Confirm which your course wants.

Is Turabian the same as Chicago?

Effectively yes. Turabian is the student-focused version of Chicago, written for research papers, theses and dissertations. It follows the same rules in a more accessible form, so ‘Turabian’ and ‘Chicago’ citations look the same.

How does a footnote differ from a bibliography entry?

The first footnote gives the author in natural order with commas and the specific page; the bibliography entry inverts the first author’s name, uses full stops between elements and omits the single page number for a whole book.

Do I still use ‘Ibid.’?

The 17th edition allows ‘Ibid.’ for a repeated source in consecutive notes, but the 18th edition prefers a shortened note (Surname, short title, page). Follow your course’s edition and be consistent.

Which edition should I use, 17th or 18th?

Use whichever your department specifies. The 18th edition (2024) is current, but the 17th remains widely taught and the citation formats are essentially identical. Pick one and apply it throughout.

How can I produce Chicago citations quickly?

Use a citation generator set to Chicago (notes–bibliography or author–date), then check note-versus-bibliography form and the correct heading. Our free Citation Generator builds Chicago citations for the source types in this guide.

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