Fiction Style Guide: Capitalization
The more you get right in your manuscript before submitting to an editor, the less work they'll have to do on mechanical issues ---- and the more time they can spend on making your writing shine. Plus, investing the time to learn the conventions of fiction style* can save you money.

*This is Articulate Editing house style, which is based on generally accepted fiction conventions (in the US) and a pinch of personal opinion. Most of what is written here will apply across the board, but if a guideline has wiggle room or exceptions, I'll let you know—and if you're working with a publisher, make sure you follow their specifications as their house style may differ slightly. (This style guide also applies to creative nonfiction.)
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Capitalization
Many people think that capitalization is part of grammar, but it's actually a matter of convention and style. While certain types of words are always capitalized, others depend on usage conventions that are flexible or change over time (usually from capital to lowercase).
While practically no English-speaking adult needs to be told to capitalize a person's name or the first word in a sentence, when to capitalize a military or political title can be confusing, partly because the convention can vary depending on whether you're writing a newspaper article, a book, or a government document.
Since we're only concerned with fiction style here, don't worry when you see different treatments elsewhere. That said, let's get on with it, shall we?
Proper nouns
A proper noun is a noun/name that designates a particular thing, not one of a category of things. Most proper nouns are capitalized, as are some terms that are derived from proper nouns. Convention changes over time, and sometimes usage is in flux: Internet is still capitalized in Merriam Webster's Unabridged, but both AP and Chicago downgraded it to lowercase a few years ago.
Terms derived from proper nouns are often capitalized. (Except when used with a nonliteral meaning or when the connection to the proper noun has become remote.) A dictionary will be helpful here. Most fiction editors use Merriam Webster's Collegiate.
German shepherd
Siamese cat
Canadian bacon
But ...
brussels sprouts
roman numerals
pasteurize (from Louis Pasteur, the man who sanitized milk)
bowdlerize (from Thomas Bowdler, the man who sanitized Shakespeare)
Adjectives derived from proper names are normally capitalized, unless the connection to the proper name has become remote over time.
Shakespearean performance
Freudian slip
But ...
herculean effort (from Hercules, Greek hero)
quixotic quest (from Don Quixote by Cervantes)
Personal names
Capitalize names with lowercase particles when they begin a sentence.
"Von Trapp, did you invite Miss duBois?"
"DuBois, did you RSVP to Mr. von Trapp?
Capitalize epithets and nicknames used instead of (or as part of) a person's name.
Alexander the Great
the Rock
But ... If the nickname is given in addition to the actual name, it's surrounded by quotation marks.
Dwayne "the Rock" Johnson (don't capitalize "the" in a nickname)
Dwayne Johnson, "the Rock," is both a wrestler and an actor. (No need for parentheses.)
Terms of endearment and insults are generally lowercased.
"Where shall we eat tonight, darling?"
"Hey, jerkface, cut that out!"
But ... if elevated to nickname status, they can be capitalized. (A wife wouldn't ask, "Where's Darling?" when her husband is missing, but a kid might dub his constant tormentor Jerkface, and use it as if it were his name.)
"Oh no! It's Jerkface! Let's get out of here."
If an insult or endearment contains a title such as Mister, Madame, or Doctor, it's always capitalized, even if it's a one--off rather than an established nickname.
"Hey, Mr. Smarty Pants, where do you think you're going?"
But ...
"Hey, mister, where you going?"
Kinship names are lowercased unless being used in place of a person's name.
I love you, Grandma.
I love my grandmother.
I have to go visit Aunt Ruth.
I have to go visit my aunt Ruth.
Deliberately lowercased names should be respected. This is true for personal names and brand names both—but avoid starting a sentence with them.
bell hooks
eBay
iPhone
Titles and honorifics
Titles (whether military, political, professional, religious, or academic) follow the same general rule. They're capitalized when they precede a given name and are used as part of that name, but are lowercased when used generally.
President Bush
Professor Donaldson
But ...
Barack Obama, president of the United States
The president is giving his inaugural address today.
John Donaldson, professor of literature
Lowercase the title when used as an noun modifier rather than as part of the name.
the former president Donald Trump
Capitalize the title when used as a direct address.
It's lovely to meet you, Mr. President.
Sergeant, what are your orders, sir? ("sir" is lowercased; see below)
Please pray for me, Reverend, for I've lost my way.
Lowercase generic titles that describe an occupation and are used as noun modifiers.
the architect Frank Gehry
Capitalize honorifics and terms of respect.
the First Lady
Your Royal Highness
His Excellency
Sir Ian McKellen
Except ...
my lady, my lord
sir, ma'am
People groups
National or ethnic group names are capitalized, as are adjectives based on those names.
Mexicans
Chinese food
an Irish person
the Sioux tribe
First Peoples
Skin color: Up until recently, the advice was to lowercase black and white, but capitalizing Black is quickly becoming the standard to shift the emphasis from skin color to shared cultural identity. And for consistency, White is often capitalized, too. The New York Times published an article about their decision to capitalize Black last year.
The trend is to not hyphenate words that indicate dual heritage such as Asian American. Without the hyphen, the first term modifies the second, so the person in question is an American (noun) with origins in Asia (adjective). With the hyphen, the implication is that the person in question isn't fully American, but some kind of hybrid. For more, check out this article by Henry Fuhrmann at Conscious Style Guide.
Categories of class, sexual orientation, or ability are lowercased.
transgender woman
the aristocracy
the middle class
deaf people
Organized groups
Organizations, government entities, institutions, religious groups, and corporations (including brand names) are usually capitalized. The generic word is usually lowercased.
The Federal Bureau of Investigation
the bureau
the Albany City Council
the city council
But unofficial political groups are usually lowercased.
moderates
anarchists
Systems of thought are lowercased even though adherents to an official group based on that system of thought are capitalized.
the Communist party
I suspect she subscribes to the tenets of communism.
She's a Communist.
Certain government entities are lowercased.