Result
No. "Of" is a two-letter preposition, and every major style guide keeps it lowercase in the middle of a title: "The Lord of the Rings," "A Tale of Two Cities." It is capitalized only as the first word, the first word of a subtitle, or, in some guides, the last word.
"Of" by Style Guide
| Style guide | "Of" mid-title | Why |
|---|---|---|
| AP | Lowercase | Prepositions of three or fewer letters stay lowercase |
| APA | Lowercase | APA lists "of" by name among the short prepositions it lowercases |
| Chicago | Lowercase | Prepositions stay lowercase regardless of length |
| MLA | Lowercase | Prepositions stay lowercase regardless of length |
| AMA | Lowercase | Prepositions of three or fewer letters stay lowercase |
| Bluebook | Lowercase | Prepositions of four or fewer letters stay lowercase |
Because all six guides agree, "of" is one of the safest words in title case. You do not need to know which style a publication follows to get it right.
Examples in Chicago Style
- The State of Content Marketing
- A Tale of Two Cities
- The Art of the Headline
- The Pros and Cons of Sentence Case
When "Of" Is Capitalized
- As the first word: "Of Mice and Men."
- After a colon, as the first word of a subtitle: "Small Words: Of Rules and Exceptions."
- As the last word in AP, Chicago, and MLA: "What Dreams Are Made Of." APA has no last-word rule and keeps it lowercase.
The Same Headline in Four Styles
| Style | "what dreams are made of" |
|---|---|
| AP | What Dreams Are Made Of |
| APA | What Dreams Are Made of |
| Chicago | What Dreams Are Made Of |
| MLA | What Dreams Are Made Of |
Related Words
"To", "for", "in", "on", and "at" are lowercase in every guide for the same reason. Phrases built on "of" keep the pattern: "Out of," "Because of," and "Instead of" capitalize the first word and lowercase "of" in Chicago style. See the full list of words that stay lowercase.
Real Titles With "Of"
- Of Mice and Men (John Steinbeck): first word, capitalized
- The Grapes of Wrath (John Steinbeck): lowercase mid-title
- The Lord of the Rings (J. R. R. Tolkien): lowercase mid-title
"Of" in Sentence Case
APA reference lists, many news sites, and most UI text use sentence case instead of title case. There, only the first word and proper nouns get capitals, so "of" is lowercase unless it starts the title: "The state of content marketing." Pick one of the two styles for a whole set of headings rather than mixing them.
Quick Answers
Should "of" be capitalized in a title?
No, not in the middle. All six major guides keep "of" lowercase unless it is the first word, starts a subtitle, or ends the title in AP, Chicago, or MLA.
Is "of" capitalized in APA style?
No. APA lists "of" among the short prepositions it lowercases.
Is "of" capitalized in Chicago style?
No. Chicago lowercases every preposition mid-title, whatever its length.
Is "of" capitalized in a name like "Bank of America"?
Follow the official name. Organizations nearly always keep "of" lowercase, as in "Bank of America" and "United States of America."