"Their" is a third-person plural possessive pronoun, used to show that something belongs to a group. The short answer: yes, capitalize "Their" in any title position across every major style guide.
This guide covers how Chicago, MLA, APA, AP, AMA, the New York Times, Wikipedia, and Bluebook each treat "their", with real examples and the common mistakes that trip writers up.
Quick Reference: "Their" by Style Guide
| Style Guide | Capitalize "Their"? | Reason |
|---|---|---|
| Chicago (CMOS) | Yes | Pronouns are always capitalized in title case |
| APA (7th edition) | Yes | Pronouns are always capitalized regardless of word length |
| MLA | Yes | Pronouns are principal words |
| AP (Associated Press) | Yes | Pronouns are capitalized; the 4-letter rule does not apply |
| AMA | Yes | Pronouns are major words |
| New York Times | Yes | All pronouns capitalized in titles |
| Wikipedia | Yes | Pronouns are major words in article titles |
| Bluebook | Yes | Pronouns capitalized in case titles and brief headings |
Across every major style, "Their" is capitalized in any title position. Pronouns, verbs, and conjunctions of 4+ letters are principal words and never get lowercased.
Chicago Manual of Style
Chicago capitalizes nouns, pronouns, verbs, adjectives, and adverbs in headline-style titles. "Their" is a pronoun and stays capitalized in any position.
MLA Style
MLA matches Chicago on pronouns: capitalize principal words including pronouns regardless of length. "Their" is always capitalized.
APA Style
APA capitalizes pronouns of any length. The "lowercase words under four letters" shortcut applies only to conjunctions, prepositions, and articles. "Their" stays capitalized.
AP Style
AP capitalizes pronouns regardless of length. The 4-letter rule applies only to prepositions and conjunctions. "Their" is always capitalized in AP headlines.
AMA Style
AMA, used in medical and health journals, treats pronouns as major words. "Their" is capitalized in any AMA title position.
New York Times Style
The Times capitalizes pronouns in headlines as principal words. "Their" is capitalized in every NYT headline that uses it.
Wikipedia Manual of Style
Wikipedia uses title case for article titles. Pronouns are capitalized as major words. "Their" is capitalized in any Wikipedia article title.
Bluebook (Legal Writing)
Bluebook capitalizes pronouns in case names, brief titles, and law-review article titles. "Their" stays capitalized in legal writing.
Real Titles That Use "Their"
- Their Eyes Were Watching God by Zora Neale Hurston. First word, pronoun.
- All the Light They Cannot See by modified Anthony Doerr title. "they/their" capitalized mid-title as pronoun.
- Sound of Their Voices. Pronoun mid-title.
- In Their Footsteps. Pronoun after preposition.
Common Mistakes
Writers sometimes lowercase "their" because it has only five letters, treating it like a short preposition. That rule applies to prepositions, conjunctions, and articles, not pronouns. "Discover their Story" should be "Discover Their Story." Marketing copy and email subject lines are the most common offenders.
Apply the Rules Automatically
Paste your title into the free title case converter at the top of the page. Pick your style and the tool handles "their" along with every other word in the title.
