Is "Through" Capitalized in a Title?

Title capitalization guide

Yes in Chicago Style and MLA Style. No in AP Style — which lowercases all prepositions.

preposition or adverb

Capitalized in 5 styles

Lowercase in 5 styles

Title Case

YES

Capitalized as a longer preposition

AP Style

Lowercase — AP lowercases all prepositions regardless of length

NYT Style

YES

Capitalized — NYT Style capitalizes prepositions

Chicago Style

YES

Capitalized — seven letters, well above the four-letter threshold

MLA Style

YES

Capitalized as a longer preposition

APA Style

Sentence case — only first word and proper nouns

AMA Style

Lowercase — AMA follows AP-style preposition rules

BB Style

YES

Every word capitalized — no exceptions

Wikipedia Style

Sentence case — only first word and proper nouns

Sentence Case

Only the first word of a title is capitalized

The full answer

"Through" is seven letters long, well above Chicago Style's four-letter lowercase threshold, so it is capitalized in Chicago Style and MLA Style. AP Style and AMA Style lowercase it along with all other prepositions.

AP Style has no length threshold for prepositions — all prepositions are lowercase. This produces a different result from Chicago Style for longer prepositions like "through," "between," "about," and "without."

"Through" can also function as an adverb — as in "seeing it through" or "working through the night." When it carries adverbial meaning rather than prepositional meaning, it is typically capitalized in all title case styles.

In Chicago Style and MLA Style, "through" in the middle of a title is capitalized. A title like "Walking Through the Storm" would capitalize "Through" under Chicago rules but lowercase it under AP rules.

"Through" illustrates the practical effect of Chicago Style's length-based preposition rule. At seven letters, it is clearly above the four-letter threshold and is capitalized in Chicago Style, MLA Style, and NYT Style.