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How to Cite in Chicago Style: Complete 18th Edition Guide

How to Cite in Chicago Style: Complete 18th Edition Guide

This guide will help you understand how to properly cite sources in Chicago format, the versatile citation style used across history, arts, and publishing, ensuring that your academic work meets the standards outlined in the Chicago Manual of Style's latest edition.

Feb 5, 2026

By

Author Picture: Joe Pacal, MSc

Joe Pacal, MSc

TL;DR

Chicago style offers two systems: notes-bibliography (footnotes + bibliography) for humanities, and author-date (parenthetical + reference list) for sciences. This guide covers both formats with examples for books, journals, and websites, plus when to use shortened footnotes and ibid. The 18th edition is current. Perfect for history, arts, and publishing.

The Official Source

The Chicago Manual of Style, 18th Edition (2024) is published by the University of Chicago Press and available in hardcover and online at chicagomanualofstyle.org.

The 18th edition—the most extensive revision in two decades—introduced guidance on citing AI-generated content, expanded inclusive language coverage, updated capitalization rules, and no longer requires publication locations in citations.

Two Citation Systems

Chicago offers two documentation styles:

  1. Notes-Bibliography (NB) — Preferred in humanities (history, literature, arts)

  2. Author-Date — Preferred in sciences and social sciences

This guide covers the Notes-Bibliography system, which uses footnotes or endnotes plus a bibliography.

Notes-Bibliography: Quick Overview

When you cite a source:

  1. Place a superscript number after the relevant text¹

  2. Include the full citation in a footnote or endnote

  3. List all sources in a bibliography at the end

Footnote vs. Bibliography Format

Footnotes and bibliography entries differ slightly in format:

Book

Footnote (first reference):

  1. Ta-Nehisi Coates, Between the World and Me (New York: One World, 2015), 45.

Shortened footnote (subsequent references):

2. Coates, Between the World and Me, 52.

Bibliography:

Coates, Ta-Nehisi. Between the World and Me. New York: One World, 2015.

Key differences: Footnotes use first name first with commas; bibliographies invert the first author's name and use periods.

Common Source Examples

Journal Article

Footnote:

  1. Susan Sontag, "Notes on 'Camp,'" Partisan Review 31, no. 4 (1964): 517.

Bibliography:

Sontag, Susan. "Notes on 'Camp.'" Partisan Review 31, no. 4 (1964): 515–30.

Chapter in Edited Book

Footnote:

  1. bell hooks, "Eating the Other," in Black Looks: Race and Representation (Boston: South End Press, 1992), 21.

Bibliography:

hooks, bell. "Eating the Other." In Black Looks: Race and Representation, 21–39. Boston: South End Press, 1992.

Website

Footnote:

  1. "Privacy Policy," Google, last modified April 17, 2024, https://policies.google.com/privacy.

Bibliography:

Google. "Privacy Policy." Last modified April 17, 2024. https://policies.google.com/privacy.

Newspaper Article

Footnote:

  1. Jennifer Schuessler, "The Surprising History of 'Woke,'" The New York Times, October 12, 2023.

Bibliography:

Schuessler, Jennifer. "The Surprising History of 'Woke.'" The New York Times, October 12, 2023.

Key 18th Edition Changes

Major updates in the 2024 edition:

  • No publication location — City/state no longer required for most sources

  • "Title Case" renamed — Now officially called "headline-style capitalization"

  • Preposition capitalization — Prepositions of five or more letters now capitalized in titles (About, Through, Without)

  • Generic singular "they" — Fully endorsed for unknown or unspecified gender

  • Initial "The" retained — Now capitalize and italicize when part of publication title (The New York Times)

  • AI citations — New guidance for citing AI-generated text and images

  • Ibid. discouraged — Shortened citations preferred over "ibid." for repeated sources

Shortened Citations

After citing a source once in full, use a shortened form for subsequent references:

First reference:

  1. Michelle Alexander, The New Jim Crow: Mass Incarceration in the Age of Colorblindness (New York: New Press, 2010), 73.

Subsequent references:

5. Alexander, New Jim Crow, 89.

The 18th edition discourages using "ibid." due to electronic publishing formats where footnotes may not appear sequentially.

Common Mistakes to Avoid

Commas vs. periods — Use commas between elements in footnotes; use periods in bibliography entries

Author name order — First name first in footnotes; last name first in bibliography (only for the first author)

Page numbers — Include specific pages in footnotes; include full page range in bibliography

Quotation marks vs. italics — Article and chapter titles in quotes; book, journal, and website titles in italics

Multiple authors — In bibliography, invert only the first author's name

Who Uses Chicago Style?

Chicago is the standard for:

  • History

  • Art history

  • Philosophy

  • Religion and theology

  • Some social sciences

  • Publishing industry

Many academic presses and scholarly journals require Chicago style. Students in these fields should master both the Notes-Bibliography and Author-Date systems.

Chicago vs. Turabian

A Manual for Writers by Kate Turabian presents a simplified version of Chicago style designed for students. Turabian and Chicago are largely compatible, but always check which your instructor requires.

Further Resources

Need help generating Chicago citations? Research tools like Wonders can export your sources in Chicago format automatically.

Frequently asked questions

When should I use Notes-Bibliography vs. Author-Date?

Notes-Bibliography (footnotes + bibliography) is standard for history, literature, and the arts. Author-Date (parenthetical + reference list) is used in sciences and social sciences. Check your discipline's convention or ask your instructor—some fields accept either.

When should I use Notes-Bibliography vs. Author-Date?

Notes-Bibliography (footnotes + bibliography) is standard for history, literature, and the arts. Author-Date (parenthetical + reference list) is used in sciences and social sciences. Check your discipline's convention or ask your instructor—some fields accept either.

When should I use Notes-Bibliography vs. Author-Date?

Notes-Bibliography (footnotes + bibliography) is standard for history, literature, and the arts. Author-Date (parenthetical + reference list) is used in sciences and social sciences. Check your discipline's convention or ask your instructor—some fields accept either.

What's the difference between ibid. and shortened footnotes?

"Ibid." (meaning "in the same place") refers to the immediately preceding footnote. Shortened footnotes (Author, Short Title, page) refer to any previously cited source. The 17th edition notes that ibid. is acceptable but no longer required—many writers now prefer shortened footnotes throughout for clarity.

What's the difference between ibid. and shortened footnotes?

"Ibid." (meaning "in the same place") refers to the immediately preceding footnote. Shortened footnotes (Author, Short Title, page) refer to any previously cited source. The 17th edition notes that ibid. is acceptable but no longer required—many writers now prefer shortened footnotes throughout for clarity.

What's the difference between ibid. and shortened footnotes?

"Ibid." (meaning "in the same place") refers to the immediately preceding footnote. Shortened footnotes (Author, Short Title, page) refer to any previously cited source. The 17th edition notes that ibid. is acceptable but no longer required—many writers now prefer shortened footnotes throughout for clarity.

Can I use Chicago for a thesis or dissertation?

Yes, Chicago is commonly accepted. However, Turabian (based on Chicago but designed for students) is often preferred for theses because it addresses issues like dissertation formatting, student-specific sources, and advisor expectations.

Can I use Chicago for a thesis or dissertation?

Yes, Chicago is commonly accepted. However, Turabian (based on Chicago but designed for students) is often preferred for theses because it addresses issues like dissertation formatting, student-specific sources, and advisor expectations.

Can I use Chicago for a thesis or dissertation?

Yes, Chicago is commonly accepted. However, Turabian (based on Chicago but designed for students) is often preferred for theses because it addresses issues like dissertation formatting, student-specific sources, and advisor expectations.

Do I need to include a bibliography if I'm using footnotes?

Yes, always include a bibliography even with full footnotes. The bibliography provides an alphabetized overview of all sources, while footnotes show where specific information came from. Some instructors allow shortened footnotes without a bibliography for very short papers, but this is rare.

Do I need to include a bibliography if I'm using footnotes?

Yes, always include a bibliography even with full footnotes. The bibliography provides an alphabetized overview of all sources, while footnotes show where specific information came from. Some instructors allow shortened footnotes without a bibliography for very short papers, but this is rare.

Do I need to include a bibliography if I'm using footnotes?

Yes, always include a bibliography even with full footnotes. The bibliography provides an alphabetized overview of all sources, while footnotes show where specific information came from. Some instructors allow shortened footnotes without a bibliography for very short papers, but this is rare.

How do I cite an ebook with no page numbers?

Use chapter numbers, section headings, or other locators. In footnotes: (chap. 4) or (under "Economic Policy"). If the ebook has stable page numbers matching print, use those.

How do I cite an ebook with no page numbers?

Use chapter numbers, section headings, or other locators. In footnotes: (chap. 4) or (under "Economic Policy"). If the ebook has stable page numbers matching print, use those.

How do I cite an ebook with no page numbers?

Use chapter numbers, section headings, or other locators. In footnotes: (chap. 4) or (under "Economic Policy"). If the ebook has stable page numbers matching print, use those.

When should I use Notes-Bibliography vs. Author-Date?

Notes-Bibliography (footnotes + bibliography) is standard for history, literature, and the arts. Author-Date (parenthetical + reference list) is used in sciences and social sciences. Check your discipline's convention or ask your instructor—some fields accept either.

Do I need to include a bibliography if I'm using footnotes?

Yes, always include a bibliography even with full footnotes. The bibliography provides an alphabetized overview of all sources, while footnotes show where specific information came from. Some instructors allow shortened footnotes without a bibliography for very short papers, but this is rare.

What's the difference between ibid. and shortened footnotes?

"Ibid." (meaning "in the same place") refers to the immediately preceding footnote. Shortened footnotes (Author, Short Title, page) refer to any previously cited source. The 17th edition notes that ibid. is acceptable but no longer required—many writers now prefer shortened footnotes throughout for clarity.

How do I cite an ebook with no page numbers?

Use chapter numbers, section headings, or other locators. In footnotes: (chap. 4) or (under "Economic Policy"). If the ebook has stable page numbers matching print, use those.

Can I use Chicago for a thesis or dissertation?

Yes, Chicago is commonly accepted. However, Turabian (based on Chicago but designed for students) is often preferred for theses because it addresses issues like dissertation formatting, student-specific sources, and advisor expectations.

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The Australian AGLC standard for citing in legal contexts.

A clearer alternative to the Bluebook for law students and practitioners.

The citation format for maths and American Mathematical Society publications.

The official citation style of the American Political Science Association developed.

The citation format for civil engineering journals and ASCE publications.

Legal citations for law students and practitioners.

The essential citation format for biology, natural sciences, and scientific research.

The IEEE citations for engineering and computer science.

The MHRA citation style guide used by arts and humanities in the UK.

The citation format for biomedical research, medical journals, and life sciences.

Writing about biblical or theological topics? SBL style is the standard for the field.

The Vancouver citation style for biomedical and health sciences.

ABNT is the official citation format used in Brazil.

The ACS citation style for chemistry and related sciences.

The standard citation style for physics journals and American Institute of Physics publications.

AMA citations for medicine and health sciences.

The APA citation style for psychology, education, and social sciences

The citation style used for sociology and social sciences.

The American Society of Mechanical Engineers numbered citation system.

Chicago-format citations used by history, arts, and humanities

GB/T 7714是中国学术写作的国家标准引用格式。

The Harvard citation style used in by UK, Australian, and international universities.

The ISO 690 Style: International Bibliography Standard (2021 Edition)

MLA citation style for humanities, literature, and languages

The citation style used in the UK by Law studies.

The student-friendly guide to Chicago-style citations for research papers and theses.

The author-date system for anthropological research.

ABNT is the official citation format used in Brazil.

ABNT is the official citation format used in Brazil.

The ACS citation style for chemistry and related sciences.

The Australian AGLC standard for citing in legal contexts.

The standard citation style for physics journals and American Institute of Physics publications.

A clearer alternative to the Bluebook for law students and practitioners.

AMA citations for medicine and health sciences.

The citation format for maths and American Mathematical Society publications.

The APA citation style for psychology, education, and social sciences

The official citation style of the American Political Science Association developed.

The citation style used for sociology and social sciences.

The citation format for civil engineering journals and ASCE publications.

The American Society of Mechanical Engineers numbered citation system.

Legal citations for law students and practitioners.

Chicago-format citations used by history, arts, and humanities

The essential citation format for biology, natural sciences, and scientific research.

GB/T 7714是中国学术写作的国家标准引用格式。

The Harvard citation style used in by UK, Australian, and international universities.

The IEEE citations for engineering and computer science.

The ISO 690 Style: International Bibliography Standard (2021 Edition)

The MHRA citation style guide used by arts and humanities in the UK.

MLA citation style for humanities, literature, and languages

The citation format for biomedical research, medical journals, and life sciences.

The citation style used in the UK by Law studies.

Writing about biblical or theological topics? SBL style is the standard for the field.

The student-friendly guide to Chicago-style citations for research papers and theses.

The Vancouver citation style for biomedical and health sciences.

The author-date system for anthropological research.

ABNT is the official citation format used in Brazil.

The Australian AGLC standard for citing in legal contexts.

A clearer alternative to the Bluebook for law students and practitioners.

The citation format for maths and American Mathematical Society publications.

The official citation style of the American Political Science Association developed.

The citation format for civil engineering journals and ASCE publications.

Legal citations for law students and practitioners.

The essential citation format for biology, natural sciences, and scientific research.

The IEEE citations for engineering and computer science.

The MHRA citation style guide used by arts and humanities in the UK.

The citation format for biomedical research, medical journals, and life sciences.

Writing about biblical or theological topics? SBL style is the standard for the field.

The Vancouver citation style for biomedical and health sciences.

ABNT is the official citation format used in Brazil.

The ACS citation style for chemistry and related sciences.

The standard citation style for physics journals and American Institute of Physics publications.

AMA citations for medicine and health sciences.

The APA citation style for psychology, education, and social sciences

The citation style used for sociology and social sciences.

The American Society of Mechanical Engineers numbered citation system.

Chicago-format citations used by history, arts, and humanities

GB/T 7714是中国学术写作的国家标准引用格式。

The Harvard citation style used in by UK, Australian, and international universities.

The ISO 690 Style: International Bibliography Standard (2021 Edition)

MLA citation style for humanities, literature, and languages

The citation style used in the UK by Law studies.

The student-friendly guide to Chicago-style citations for research papers and theses.

Finding these guides useful?

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Try these techniques in Wonders—an AI workspace for literature review. 21 days free. Students get 50% off.

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Try these techniques in Wonders—an AI workspace for literature review.

21-day Free Trial (card required).

Students get 50% off.

Finding these guides useful?

Try these techniques in Wonders—an AI workspace for literature review. 21 days free. Students get 50% off.