How to Cite Sources According to the Chicago Style Guide?

The Chicago Manual of Style, established in 1906 by the University of Chicago Press, is the basis of many methods of formatting research papers and literary works. Learning how to cite using this guide can help you avoid plagiarism and term paper problems. In this article, we provide a comprehensive breakdown of the Chicago citation rules.

Chicago Style Citations

There are two types of citation styles used when formatting sources according to the Chicago Manual of Style:

  1. Humanities Style (Notes and Bibliography) and,
  2. Scientific Style (Author-Date).

Each style has its own set of rules and you must use them correctly.

1. Humanities Style

The Humanities style requires footnotes or endnotes and a bibliography. A reader should be able to use the footnotes or endnotes to go back to the source and easily find the original.

Here are the rules of citing footnotes/endnotes for your paper:

  • Footnotes and Endnotes: The first time you use a source, use a full citation that includes the source’s author, title, and all other relevant information. Include page numbers as well if you have them. Subsequent citations can just use the last name of the author and the publication year.
  • Bibliography: Bibliographies are used to list all the sources you’ve used. Make sure everything is listed in the correct order: author, title, publisher, date etc.

2. Scientific Style

The Scientific style requires the author-date system, which is commonly used in scientific and social sciences papers. The author’s last name and date of publication should be included in parentheses in the text — for example, (Smith 2019).

The author-date system also requires a list of sources at the end of the paper or document. This is referred to as the ‘References’ section. Again, make sure all sources are listed in the correct order: author, title, publisher, date etc.

In-Text Citations Rules In Chicago

  • When citing sources in the text, include the author’s last name, a space, and the year of publication. For example, “Smith (2019) was the first to document…”
  • If there is no author, use the title of the source instead. For example, “(“How to Cite Sources” 2019) was the first to document…”
  • If the author is listed in the text, you do not need to include the date in parentheses. For example, “Smith (2019) was the first to document…”


Now that you know the rules of how to cite sources according to Chicago style, you can be sure to use them correctly when formatting your paper.

Remember to include footnotes for the Humanities style, and an Author-Date system for the Scientific style. Each method also requires a lists of sources at the end. Following these guidelines will help you create polished and properly cited research papers.

Learning Resources

PDF Chicago Manual Style Guide