Chicago Style Guide — Footnotes & Bibliography (2026)

Chicago Manual of Style 17th edition: footnote-bibliography style for history and humanities, plus author-date for sciences.

Footnote Format (First Cite)

1. John Smith, Title of Book (Publisher, 2024), 14.

Footnote Format (Subsequent)

2. Smith, Title, 22.

Bibliography Entry

Smith, John. Title of Book. Publisher, 2024.

Frequently Asked Questions

When do I use footnotes vs author-date?

Footnotes for history/humanities; author-date (similar to APA) for natural and social sciences.