Chicago/Turabian Citation Style: Complete Guide

Chicago citation style — often used alongside the simpler Turabian format — is one of the most widely used referencing systems in the humanities, social sciences, and history. If your professor asks for "footnotes and a bibliography," chances are they want Chicago style.

This guide explains both Chicago systems, shows you how to format citations for different source types, and highlights the most common mistakes students make.

Two Systems: Notes-Bibliography vs Author-Date

The Chicago Manual of Style (17th edition) offers two distinct citation systems:

• Notes-Bibliography (NB) — Uses footnotes or endnotes plus a bibliography. Preferred in humanities (history, literature, arts).
• Author-Date (AD) — Uses parenthetical in-text citations plus a reference list. Preferred in social sciences and sciences.

Always check with your professor or department which system to use. When in doubt, Notes-Bibliography is the "classic" Chicago approach.

Notes-Bibliography System

How Footnotes Work

Place a superscript number at the end of a sentence or clause where you reference a source. At the bottom of the page (footnote) or end of the paper (endnote), provide the full citation details.

Footnote Format — Book

First citation:

1. Author First Last, Title of Book (Place: Publisher, Year), page number.

Example: 1. Sarah Johnson, Modern Academic Writing (Oxford: Oxford University Press, 2024), 45.

Subsequent citations:

2. Johnson, Modern Academic Writing, 78.

Footnote Format — Journal Article

3. Author First Last, "Article Title," Journal Name Volume, no. Issue (Year): page range.

Example: 3. David Chen, "Critical Analysis in Higher Education," Journal of Academic Research 12, no. 3 (2025): 234–256.

Footnote Format — Website

4. Author or Organization, "Page Title," Website Name, published or accessed date, URL.

Bibliography Entries

The bibliography lists all sources alphabetically by the author's last name. The format differs slightly from footnotes — the author's last name comes first:

Johnson, Sarah. Modern Academic Writing. Oxford: Oxford University Press, 2024.

Author-Date System

Instead of footnotes, you place citations in parentheses within the text:

(Johnson 2024, 45)

The reference list at the end follows a similar format to the bibliography but includes the year immediately after the author's name:

Johnson, Sarah. 2024. Modern Academic Writing. Oxford: Oxford University Press.

Chicago vs Other Citation Styles

• Chicago vs APA — APA is more structured and rule-bound; Chicago offers more flexibility and uses footnotes (NB system)
• Chicago vs MLA — MLA uses parenthetical citations and a Works Cited page; Chicago NB uses footnotes and a bibliography
• Chicago vs Harvard — Harvard is similar to Chicago Author-Date but with some formatting differences

Common Chicago Style Mistakes

• Mixing Notes-Bibliography and Author-Date systems in the same paper
• Using "Ibid." incorrectly — it refers to the immediately preceding footnote only
• Forgetting to include a bibliography alongside your footnotes
• Incorrect punctuation in footnotes (commas vs periods)
• Not including page numbers for direct quotes
• Using the wrong edition of the Chicago Manual

"Consistency is the golden rule of Chicago style. Pick one system and follow it throughout your entire paper."

Free Chicago Citation Tools

• ZoteroBib — Free, instant Chicago citations from URLs, ISBNs, or DOIs
• Zotero — Reference manager with full Chicago style support
• Cite This For Me — Quick online Chicago citation generator
• Purdue OWL — Comprehensive Chicago style formatting guide

Wrapping Up

Chicago style may seem complex at first, but once you understand the two systems, it becomes second nature. Focus on consistency, always include page numbers for direct quotes, and use a citation management tool to save time.

If you need your paper properly formatted in Chicago style, or any citation style, we're here to help.