Few punctuation marks inspire as much debate as the Oxford comma. Some writers defend it passionately; others think it’s clutter. Both groups are writing correct English, because the Oxford comma is a matter of style, not a fixed grammar rule.
Still, there is a clear answer to the question in the title. Yes, many Americans use it, and most major American style guides recommend it. The main exception is journalism.
Below, we explain what the Oxford comma is, which style guides use it, when it really matters, and the court case that made it famous.
What Is the Oxford Comma?
The Oxford comma, also called the serial comma, is the comma placed before the final and or or in a list of three or more items.
- With the Oxford comma: We bought apples, oranges, and pears.
- Without the Oxford comma: We bought apples, oranges and pears.
Both sentences are clear, and both are acceptable. The name comes from Oxford University Press, whose editors traditionally used it. Despite the British name, the serial comma is arguably more common in American publishing than in British publishing today. Our guide to American vs. British English covers more differences like this.
The comma only applies to lists of three or more. With two items, you don’t need a comma: “salt and pepper,” not “salt, and pepper.”
Which US Style Guides Use It?
American style guides split on this question, which is why you see both versions in print.
| Style guide | Used mainly for | Oxford comma? |
|---|---|---|
| The Chicago Manual of Style | Books, many publishers | Yes, recommended |
| APA Style | Psychology, social sciences, many academic papers | Yes |
| MLA Style | Literature, humanities, many school essays | Yes |
| The Associated Press Stylebook (AP) | News, journalism, many public relations and corporate writers | No in simple series, but yes when needed to prevent confusion |
AP’s position is often misunderstood. AP doesn’t ban the Oxford comma. It omits the comma in simple series (“red, white and blue”) but uses it when the final items are complex or when leaving it out could cause confusion.
If you are writing a school paper, a research article, or a book, you’ll almost certainly use the Oxford comma. If you write for a newspaper or a company that follows AP style, you’ll usually leave it out.
When the Oxford Comma Prevents Confusion
Supporters of the serial comma point to sentences where leaving it out creates a second, unintended meaning. The classic example looks like this:
- Without: I’d like to thank my parents, Taylor Swift and the Pope.
- With: I’d like to thank my parents, Taylor Swift, and the Pope.
Without the comma, “Taylor Swift and the Pope” can be read as a description of “my parents.” With the comma, it’s clearly a list of three separate thank-yous.
Here are two more:
-
Ambiguous: The menu offered soup, chicken and rice. Is “chicken and rice” one dish or two items?
-
Clear: The menu offered soup, chicken, and rice.
-
Ambiguous: She left her estate to her sons, Jim and Kevin. Does she have two sons named Jim and Kevin, or did she leave it to her sons plus two other people?
-
Clear (four or more heirs): She left her estate to her sons, Jim, and Kevin.
It can’t fix everything
To be fair, the Oxford comma can create its own ambiguity in rare cases.
- She thanked her mother, Maria, and the coach.
Is Maria her mother, or a third person? Here the comma makes “Maria” look like an appositive (a renaming of “her mother”). The best fix is often to reorder the list: “She thanked the coach, Maria, and her mother.”
Quick rule: If a list could be read two ways, rewrite it. Adding or removing a comma helps most of the time, but reordering the items is sometimes the only clean fix.
The Maine Dairy Case: A $5 Million Comma
The Oxford comma made national news in 2017 thanks to a lawsuit over overtime pay. In O’Connor v. Oakhurst Dairy, delivery drivers for a Maine dairy company argued they were owed overtime.
Maine’s overtime law listed activities that were exempt from overtime. The list ended with the words “packing for shipment or distribution” with no comma before “or distribution.” The question was whether “distribution” was its own exempt activity, which would cover the drivers, or whether the law only exempted packing for shipment or distribution, which the drivers didn’t do.
The U.S. Court of Appeals for the First Circuit ruled in favor of the drivers. The court found that the missing comma made the law ambiguous, and it resolved that ambiguity in the drivers’ favor. The case later settled for $5 million.
The case doesn’t prove that one style is “right.” It does show how much a single comma can matter when a sentence is read very closely, as contracts and laws are.
When to Use It and When to Leave It Out
Because the Oxford comma is a style choice, the real rule is: follow the style guide that applies to you.
Use it when
- Your school, publisher, or employer follows Chicago, APA, or MLA.
- You are writing contracts, policies, instructions, or anything where precision is critical.
- The list items contain and themselves: “Our options are pasta, rice and beans, and salad.”
- Leaving it out would make the last two items look like a pair or a description.
Leave it out when
- You are writing in AP style (news, many press releases and corporate blogs) and the series is simple.
- Your organization’s style guide says so.
Lists with complex items
When list items contain internal commas, switch to semicolons: “The tour stops in Austin, Texas; Denver, Colorado; and Portland, Oregon.” Most style guides keep the semicolon before the final item. Our full punctuation guide explains semicolons and other comma rules.
How to Stay Consistent
The biggest mistake isn’t choosing the “wrong” style. It’s mixing both in the same document.
- Pick one style per project. If your first list uses the Oxford comma, every list should.
- Check your style guide once. If none applies, choose the Oxford comma for clarity. That’s what we recommend at GrammarVista.com USA for most general writing.
- Search before you finish. Scan for “, and” and “ and” in lists to catch inconsistencies.
- Note it in shared documents. On a team, write the choice into your style sheet so everyone follows it.
Quick rule: Consistency matters more than the choice itself. One style, every list, the whole document.
The Bottom Line
Americans do use the Oxford comma, and Chicago, APA, and MLA all call for it. AP style, used by most news outlets, leaves it out of simple lists but adds it when needed for clarity. Neither choice is a grammar error. If you have no style guide to follow, the Oxford comma is the safer default, because it prevents more confusion than it causes. Whatever you choose, use it consistently. For more everyday rules, browse our grammar rules guide.