Chicago Citation Style: The Complete 2026 Guide (17th Edition)

Chicago citation style is one of the oldest and most authoritative referencing systems in academic writing — and one of the most misunderstood. Whether you are writing a history dissertation, a philosophy essay, or a social sciences research paper, getting Chicago style right in 2026 means knowing which of its two systems applies to your work, how footnotes differ from endnotes, and exactly how to format every source type. This guide covers every rule in the Chicago Manual of Style 17th edition (CMOS 17) with 25+ copy-paste examples, so you can cite with confidence.

If you have ever stared at a footnote wondering whether to italicize the journal title or put it in quotes, you are not alone. CMOS 17 runs to over 1,000 pages. This guide distills what thesis and dissertation students actually need — from the first footnote to the final bibliography entry — with a clear explanation of notes-bibliography versus author-date, the two systems Chicago offers.

Notes-Bibliography vs. Author-Date: Which System to Use

The single most important decision in Chicago style is choosing the right system. CMOS 17 provides explicit guidance on which disciplines use which format:

If your department or journal has not specified a system, check the style your field’s leading journals use. History journals almost universally require notes-bibliography. Sociology and political science journals typically prefer author-date. When in doubt, ask your supervisor before writing a single citation — retrofitting 200 footnotes into parenthetical citations is not a productive use of your final week before submission.

Footnotes vs. Endnotes Explained

Both footnotes and endnotes use identical formatting in Chicago style — the only difference is physical placement. A footnote appears at the bottom of the page on which the superscript number appears, separated from the body text by a short horizontal rule. An endnote appears on a dedicated “Notes” page at the end of the chapter or document, before the bibliography.

Footnotes are standard in most academic journals and published books because readers can see the citation without flipping pages. Endnotes are common in book manuscripts where dense footnotes would disrupt reading. Many universities accept either form; check your institutional guidelines. In Microsoft Word, insert footnotes via References → Insert Footnote (Ctrl+Alt+F) and endnotes via References → Insert Endnote (Ctrl+Alt+D).

Notes-Bibliography: 15+ Formatted Examples

In notes-bibliography, every source gets a full note on first reference and a short note on subsequent references. The bibliography at the end lists all sources alphabetically by author last name.

Books

Single author — first note:
1. John Darwin, After Tamerlane: The Rise and Fall of Global Empires (London: Allen Lane, 2007), 112.

Single author — short note:
2. Darwin, After Tamerlane, 198.

Single author — bibliography:
Darwin, John. After Tamerlane: The Rise and Fall of Global Empires. London: Allen Lane, 2007.

Two authors — note:
3. Robert Darnton and Daniel Roche, eds., Revolution in Print: The Press in France 1775–1800 (Berkeley: University of California Press, 1989), 45.

Two authors — bibliography:
Darnton, Robert, and Daniel Roche, eds. Revolution in Print: The Press in France 1775–1800. Berkeley: University of California Press, 1989.

Four or more authors — note (use “et al.” after first):
4. Sarah Mitchell et al., Global Histories of Knowledge (Cambridge: Cambridge University Press, 2023), 78.

Edited book — note:
5. Lynn Hunt, ed., The New Cultural History (Berkeley: University of California Press, 1989), 3.

Chapter in edited book — note:
6. Roger Chartier, "Texts, Printing, Readings," in The New Cultural History, ed. Lynn Hunt (Berkeley: University of California Press, 1989), 154–175.

Chapter in edited book — bibliography:
Chartier, Roger. "Texts, Printing, Readings." In The New Cultural History, edited by Lynn Hunt, 154–175. Berkeley: University of California Press, 1989.

Journal Articles

Print journal — note:
7. Dipesh Chakrabarty, "The Climate of History: Four Theses," Critical Inquiry 35, no. 2 (2009): 197–222.

Print journal — bibliography:
Chakrabarty, Dipesh. "The Climate of History: Four Theses." Critical Inquiry 35, no. 2 (2009): 197–222.

Online journal with DOI — note:
8. Emma Hart, "Urban Economies in the Colonial Americas," Journal of Early American History 12, no. 1 (2022): 34, https://doi.org/10.1163/18770703-01201004.

Websites and Online Sources

Webpage — note:
9. Hannah Ritchie, "Smoking," Our World in Data, last modified January 2024, https://ourworldindata.org/smoking.

Webpage — bibliography:
Ritchie, Hannah. "Smoking." Our World in Data. Last modified January 2024. https://ourworldindata.org/smoking.

No author, webpage — note:
10. "Chicago Manual of Style Online," University of Chicago Press, accessed April 12, 2026, https://www.chicagomanualofstyle.org.

Theses and Dissertations

PhD thesis — note:
11. Maria Santos, "Colonial Networks in the Eighteenth-Century Atlantic" (PhD diss., Harvard University, 2021), 89.

PhD thesis — bibliography:
Santos, Maria. "Colonial Networks in the Eighteenth-Century Atlantic." PhD diss., Harvard University, 2021.

Author-Date: 10+ Formatted Examples

In the author-date system, in-text citations appear as (Last Year, page). The reference list at the end follows the same alphabetical order as a bibliography but places the year immediately after the author name.

Books

In-text: (Darwin 2007, 112)

Reference list — single author:
Darwin, John. 2007. After Tamerlane: The Rise and Fall of Global Empires. London: Allen Lane.

Reference list — two authors:
Darnton, Robert, and Daniel Roche, eds. 1989. Revolution in Print: The Press in France 1775–1800. Berkeley: University of California Press.

Reference list — edited chapter:
Chartier, Roger. 1989. "Texts, Printing, Readings." In The New Cultural History, edited by Lynn Hunt, 154–175. Berkeley: University of California Press.

Journal Articles

In-text: (Chakrabarty 2009, 200)

Reference list — print:
Chakrabarty, Dipesh. 2009. "The Climate of History: Four Theses." Critical Inquiry 35 (2): 197–222.

Reference list — with DOI:
Hart, Emma. 2022. "Urban Economies in the Colonial Americas." Journal of Early American History 12 (1): 22–56. https://doi.org/10.1163/18770703-01201004.

Websites

In-text: (Ritchie 2024)

Reference list:
Ritchie, Hannah. 2024. "Smoking." Our World in Data. Last modified January 2024. https://ourworldindata.org/smoking.

No Author

In-text (use short title): (Chicago Manual 2017, 14.5)

Reference list:
The Chicago Manual of Style. 2017. 17th ed. Chicago: University of Chicago Press.

AI-Generated Content (CMOS 17 Guidance for 2026)

CMOS guidance updated for AI tools recommends treating AI-generated text like a personal communication — not reproducible by readers. Note the tool, version, and date of generation:

Note: 12. Text generated by ChatGPT (OpenAI, GPT-4o), April 2026, in response to a prompt about colonialism, in the author's possession.

Bibliography and Reference List Formatting Rules

Whether you are using notes-bibliography or author-date, the end-of-document list follows these universal Chicago rules:

• Hanging indent: First line flush left; subsequent lines indented 0.5 inches (1.27 cm).
• Alphabetical order: By author last name. Multiple works by the same author ordered chronologically.
• Same author, multiple works: Replace the author name with a 3-em dash (———) for the second and subsequent entries.
• No author: Alphabetize by the first significant word of the title (ignore “A,” “An,” “The”).
• Book titles: Italicized.
• Article and chapter titles: In quotation marks, not italicized.
• Journal titles: Italicized.
• Publisher location: Required for pre-2000 books in most style guides; increasingly optional for well-known publishers in CMOS 17 (section 14.29), but still recommended for academic papers.
• DOI vs. URL: Prefer DOI when available. For URLs without DOIs, include an access date only for content that may change (websites, social media). Stable databases do not require access dates.

Special Cases: No Author, Multiple Authors, Same Author

No Author

If no author is identified, begin the note and bibliography entry with the title. In notes, you may shorten the title after the first citation. Do not use “Anonymous” unless the work was published under that name.

Multiple Authors

For two or three authors, list all names in both notes and bibliography. For four or more, use the first author followed by “et al.” in notes. In the bibliography (NB system) or reference list (AD system), list all authors — no matter how many — with no “et al.”

Same Author, Multiple Works in Same Year (Author-Date)

Add a lowercase letter after the year: (Mitchell 2023a, 45) and (Mitchell 2023b, 102). In the reference list, list them alphabetically by title and append the same letters.

Corporate or Institutional Author

Use the institution as the author: World Health Organization. 2024. Global Report on Tobacco. Geneva: WHO. In notes: World Health Organization, Global Report on Tobacco (Geneva: WHO, 2024), 12.

Secondary Sources (“Quoted in”)

Cite the original source when possible. When unavailable, note: 13. Adam Smith, The Wealth of Nations (1776), 45, quoted in Amartya Sen, The Idea of Justice (Cambridge, MA: Harvard University Press, 2009), 12.

Chicago vs. APA vs. MLA: Key Differences

Choosing between citation styles is a common source of confusion. Here is how Chicago compares to the two other dominant systems. For a deeper comparison, see our guide to APA vs MLA vs Chicago with a full comparison chart and the detailed Chicago vs APA vs MLA citation style breakdown.

For a complete breakdown of when to use each style, see what citation style to use for your thesis. If your department requires MLA, our MLA format guide (9th edition) covers all current rules. For APA-specific formatting, the APA citation format guide walks through the 7th edition step by step.

Automate Chicago Citations with Tesify

Manually formatting 40–80 Chicago citations is time-consuming and error-prone. A single misplaced comma or missing italics can result in examiner comments or journal revisions. Tesify’s Auto Bibliography supports CMOS 17th edition for both notes-bibliography and author-date systems.

The workflow is straightforward: paste a DOI, ISBN, or URL into Tesify, select Chicago 17th edition and your preferred system (NB or AD), and the tool generates a correctly formatted footnote, endnote, short-form note, and bibliography entry simultaneously. For sources without identifiers — archival documents, manuscripts, personal communications — the guided form ensures every required field is captured.

• Supports all CMOS 17 source types including theses, podcasts, streaming video, and social media
• Exports the full bibliography as a Word-compatible .docx or plain text for direct paste
• Detects whether you need a footnote or parenthetical based on your selected system
• Integrates with the Tesify thesis writing environment — citations are linked to your draft sections

For academic writing teams and doctoral students managing hundreds of sources across a multi-year project, automated citation management is not a luxury — it is the only way to maintain consistency across chapter revisions. The product details are available on the Tesify Auto Bibliography page.

Frequently Asked Questions