Is Of Capitalized In Titles? | Title Rules Made Clear

You’ve seen it a hundred times: a book jacket that says King Of the Hill, then a blog post that says King of the Hill. Same words, different casing. That tiny two-letter word can make a title look polished or a bit off.

This guide gives you a rule you can follow, plus the few spots where the rule bends. You’ll get a fast way to title-case “of” for school papers, blog headlines, book titles, and WordPress posts.

It also helps you keep headings consistent site-wide.

Why small words trip people up

Most title styles treat short function words (like “of,” “in,” “to,” “and”) differently from content words (like “Mountain,” “Recipe,” “Research”). The trouble is that different style guides draw the line in slightly different places, and many tools apply their own logic.

If you copy a title from a PDF, paste it into a CMS, then run a “title case” button, you can end up with three versions of the same line. Readers notice that inconsistency even if they can’t name the rule.

Title case rules for “of” at a glance

Use this table as your fast check. It blends the shared rule across major style guides, then marks the common exceptions you’ll see in academic and publishing settings.

Where “of” appears	Capitalize “of”?	What to do
Middle of a title	No	Keep it lowercase: The Sound of Music.
First word of the title	Yes	Capitalize it: Of Mice and Men.
Last word of the title	Yes	Capitalize it: Portrait Of (rare, but possible).
After a colon in a subtitle	Usually yes	Capitalize the first word after the colon; “Of” can be that word.
Part of a proper name	Match the name	Keep the official casing: Bank of America.
Title written in sentence case	No (unless first word)	Sentence case uses normal sentences: “of” stays lowercase.
All caps or small caps design	Style choice	Design may force caps; follow the brand or publisher spec.
Quoted title inside running text	Follow the source	Don’t “fix” a published title when citing it.

Is Of Capitalized In Titles? The rule you can follow

In headline-style capitalization (often called title case), “of” stays lowercase in the middle of a title. That single rule handles the bulk of real-world titles: book names, article headlines, movie titles, and blog posts.

Then come the three situations that flip the switch:

• Start of the title: If the title begins with “Of,” capitalize it.
• End of the title: If the title ends with “of,” capitalize it (this is uncommon, but it’s the standard rule).
• Official name: If “of” is inside a proper name or trademark, keep the official casing, even if it breaks your house rule.

Why most styles keep “of” lowercase

Title case is built to make the content words pop. “Of” usually doesn’t carry the meaning on its own; it connects the meaning words. Lowercasing it keeps the eye on what readers skim for: nouns, verbs, and adjectives.

That’s why “War of the Worlds” reads clean, while “War Of The Worlds” can feel like a sign that the title was auto-cased.

What major style guides say

If you’re writing for a class, a journal, or a client, the safest move is to follow the guide they name. Many schools accept any consistent style, but some instructors want one system.

Two pages worth bookmarking are APA’s title case notes and Microsoft’s capitalization guidance. They both spell out when short words stay lowercase, and they show how subtitles and headings should be treated in formal writing.

See APA title case capitalization
and Microsoft style guide capitalization.

Quick steps to title-case “of” without a tool

When you’re writing by hand, this is the fastest routine that keeps you consistent.

1. Write the title normally first. Don’t worry about caps yet.
2. Capitalize the first word and the last word.
3. Capitalize main words: nouns, pronouns, verbs, adjectives, and adverbs.
4. Keep short connecting words lowercase: “of,” “and,” “to,” “in,” “for,” “on,” and similar words.
5. After a colon, capitalize the first word of the subtitle.
6. Check proper names and trademarks; match their official casing.

This routine gets you the right answer even when an auto-casing tool gets cute with edge situations.

What counts as “the first word” after punctuation

In many title styles, a colon splits a main title and a subtitle. The first word after a colon is treated like a new start, so it gets a capital letter. If that word is “of,” it becomes “Of.”

Dashes and parentheses vary by house style. If your publisher has a rule, follow it. If not, keep your casing consistent across your site.

Hyphenated phrases and line breaks

Hyphenated titles can trick your eye because you’re just reading one unit split by punctuation. Treat the phrase as a normal title, then apply the same “major word vs short word” habit. In “End-of-Year Review,” the nouns stay capped, while “of” stays lowercase because it’s still a short connector inside the phrase.

If a title wraps onto a second line (book jackets do this a lot), don’t let the line break push you into capping “of.” A wrap is only layout. The casing rule stays the same.

• If a hyphen connects two main words, cap both parts: “Long-Term.”
• If a hyphen connects a main word and a short connector, keep the connector lowercase: “End-of-Year.”
• If you’re matching a published title, copy its casing even if you’d write it differently.

Common traps that make “of” look wrong

Most mistakes come from one of these habits. Fix them once and your titles start to feel steady.

Relying on a title case button without checking

Word processors, plugins, and headline generators don’t share one standard. Some treat each word after a colon as a “major” word, some treat short words as lowercase no matter where they sit, and some follow their own list of “minor words.”

That’s why you can type “the art of war: a study of strategy” and get a result that feels uneven. A quick scan for “Of” in the middle of a title usually catches the slip.

Tool settings that change the result

Some apps offer more than one casing option, even if they all sound like “title case.” Word has a toggle that can flip between sentence case and title case. Some headline tools let you choose “AP,” “Chicago,” or “smart” casing. If you’re working for a class or a client, pick one system once, then stick with it for each title on that project. When you switch systems mid-stream, “of” is often the first word that gives it away.

Mixing title case and sentence case

Sentence case is the normal sentence style: only the first word and proper names get capitals. Many academic headings use sentence case, and many news headlines use title case. Mixing the two inside one page can look messy.

Pick one for your site posts, then stick to it. If your theme prints titles in title case, keep your headings inside the post in title case too, or keep them all in sentence case. Either works if you stay consistent.

Copying a published title and “fixing” it

When you cite a book, paper, or film, treat its title as a proper name. Keep the casing used by the publisher, even if you would have cased it differently. This matters in citations and bibliographies, where exact titles help readers find sources.

Capitalizing “of” in real writing situations

Rules feel simple until you hit a real deadline: a YouTube title, a WordPress slug, a book review header, and a paper heading all in one day. Here’s how to handle the usual places you’ll see “of.”

Blog posts and WordPress titles

For blog titles, title case is a solid default because it reads like a headline. In that setting, keep “of” lowercase unless it starts the title or follows a colon as the first word of the subtitle.

Your URL slug is different. Slugs are often lowercase for readability and consistency. If you’re asking “is of capitalized in titles?” in the context of slugs, the answer is no: keep it lowercase, keep it short, and use hyphens.

School papers and academic headings

Many instructors care more about consistency than micro rules. Still, if your class uses APA, MLA, or Chicago, use the guide’s heading rules and match your reference list style.

APA uses title case for paper titles and headings at certain levels, while it uses sentence case for reference list titles of articles and chapters. That split surprises students, so it’s worth checking the guide before you format your final draft.

Books, films, and proper titles

Published creative works often follow a house style, and that style can bend. Some publishers cap small words for visual balance, some keep them lowercase, and some use small caps. If you’re writing about a work, match the work’s own casing in your text and citations.

UI labels, buttons, and menu items

In apps and menus, sentence case is common because it reads fast. If your UI uses sentence case, “of” stays lowercase unless it starts the label. If your UI uses title case across each label, then the standard title case rule applies.

Table check: Choose the right casing for your context

This second table is a quick chooser. Pick your context, then follow the matching casing style and the “of” rule that comes with it.

Context	Recommended casing	“Of” rule
Blog post title	Title case	Lowercase in the middle; cap at start/end.
Academic paper title (APA)	Title case	Lowercase in the middle; cap after colon if it starts subtitle.
Reference list article title (APA)	Sentence case	Lowercase unless first word or proper name.
Email subject line	Title case or sentence case	Match your team’s habit; stay consistent.
UI button or menu label	Sentence case	Lowercase unless first word.
Book title in a review	Match the published title	Keep the official casing from the title page or publisher page.

A quick self-check before you publish

Before you hit publish, run a ten-second scan. It catches the most common slip without slowing you down.

• Read the title out loud once. If “Of” pops in the middle, it’s a likely mistake.
• Check the first and last words. They should be capped in title case.
• Scan for a colon. The first word after it should be capped.
• Check brand names. Keep their official casing.
• Make sure your page uses one casing style for titles and headings.

That’s it. When you follow that small routine, the question “is of capitalized in titles?” stops being a recurring edit note and becomes a solved problem.