Result
It depends on the style guide. "About" is a five-letter preposition. AP, APA, AMA, and Bluebook capitalize prepositions that long, so they write "About." Chicago and MLA lowercase prepositions at any length, so "about" stays lowercase there unless it is the first or last word, or works as an adverb.
"About" by Style Guide
| Style guide | "About" mid-title | Why |
|---|---|---|
| AP | Capitalize | Prepositions of four or more letters are capitalized |
| APA | Capitalize | Words of four or more letters are capitalized |
| Chicago | Lowercase | Prepositions are lowercase at any length |
| MLA | Lowercase | Prepositions are lowercase at any length |
| AMA | Capitalize | Prepositions longer than three letters are capitalized |
| Bluebook | Capitalize | Prepositions longer than four letters are capitalized ("about" has five) |
The Same Headline in Four Styles
| Style | "everything you need to know about title case" |
|---|---|
| AP | Everything You Need to Know About Title Case |
| APA | Everything You Need to Know About Title Case |
| Chicago | Everything You Need to Know about Title Case |
| MLA | Everything You Need to Know about Title Case |
| Style | "a book about writing" |
|---|---|
| AP | A Book About Writing |
| APA | A Book About Writing |
| Chicago | A Book about Writing |
| MLA | A Book about Writing |
When Chicago Capitalizes "About"
- Last word: "Something to Talk About" ends with a capital in AP, Chicago, and MLA.
- As an adverb: in "Up and About," nothing follows "about," so it is an adverb and capitalized.
- First word: "About a Boy."
Related Words
Other prepositions of five or more letters split the guides the same way, including "after", "among", "between", and "without". See title case prepositions for the full cutoff rules.
Real Titles With "About"
- About a Boy (Nick Hornby): first word
- Something to Talk About (song): last word
"About" 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 "about" is lowercase unless it starts the title: "Everything you need to know about title case." Pick one of the two styles for a whole set of headings rather than mixing them.
Quick Answers
Should "about" be capitalized in a title?
In AP, APA, AMA, and Bluebook, yes. In Chicago and MLA, no, unless it is first, last, or an adverb.
Is "about" capitalized in APA?
Yes. "About" has five letters, and APA capitalizes words of four letters or more.
Is "about" capitalized in Chicago style?
Not as a preposition. Chicago lowercases prepositions regardless of length.