Yes, many Americans use the Oxford comma, and most major American style guides recommend it. Chicago, APA, and MLA all call for it. The main exception is journalism: AP style leaves it out of simple lists.
Either way, the Oxford comma is a matter of style, not a grammar rule. Here at GrammarVista.com USA, we explain what the comma does, who uses it, when it really matters, and the court case that made it famous.
Key Takeaways
- The Oxford (serial) comma is the comma before the final and or or in a list of three or more items.
- Chicago, APA, and MLA use it; AP omits it in simple lists but adds it when needed for clarity.
- It can prevent ambiguity, though in rare cases reordering the list is the only clean fix.
- Consistency matters more than the choice: one style, every list, the whole document.
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 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 differences covers more contrasts like this, and the US vs UK English section gathers them all.
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, so 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 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.
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 read as a description of “my parents.” With it, the list clearly names three thank-yous.
| Ambiguous | The question | Clear |
|---|---|---|
| The menu offered soup, chicken and rice. | Is “chicken and rice” one dish or two items? | The menu offered soup, chicken, and rice. |
| She left her estate to her sons, Jim and Kevin. | Are Jim and Kevin her sons, or two other heirs? | She left her estate to her sons, Jim, and Kevin. (four or more heirs) |
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 for the drivers. Its March 2017 opinion opens with “For want of a comma, we have this case,” and it resolved the law’s ambiguity in the drivers’ favor. The case later settled for $5 million.
The case doesn’t prove one style is “right,” but it shows how much a comma can matter in contracts and laws.
When to Use It and When to Leave It Out
Because the Oxford comma is a style choice, the real rule is simple: 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 guide to American punctuation rules explains semicolons and the rest of the comma rules. The Purdue OWL’s comma quick rules also list the series comma among the core uses.
Don’t confuse it with date commas
Date commas aren’t optional: “On July 4, 1776, the declaration was signed.” See how to write dates in American English.
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 GrammarVista.com USA recommends for most general writing.
- Search before you finish. Scan for “, and” and ” and” in lists to catch inconsistencies.
- Note it in shared documents. Put the choice in your team’s style sheet.
Quick rule: Consistency matters more than the choice itself. One style, every list, the whole document.
The Bottom Line
Neither choice is a grammar error. If no style guide applies, the Oxford comma is the safer default, because it prevents more confusion than it causes.
For more on every mark, browse the Punctuation section, brush up with our American English grammar rules, or start from the GrammarVista.com USA homepage.
Frequently Asked Questions
Is the Oxford comma grammatically required?
No. The Oxford comma is a style choice, not a grammar rule, so lists with and without it are both correct. What matters is following the style guide your school, publisher, or employer uses. If no guide applies, the serial comma is a safe default because it prevents more misreadings than it causes.
Does AP style ever use the Oxford comma?
Yes. AP omits the serial comma in simple series such as “red, white and blue,” but it adds the comma when the final items are complex or when leaving it out could confuse readers. So AP doesn’t ban the Oxford comma; it simply treats it as a tool for clarity rather than a default.
Why is it called the Oxford comma?
The name comes from Oxford University Press, whose editors and printers traditionally used the comma before the final item in a list. It is also called the serial comma, especially in American style guides. Despite the British name, the comma is arguably more common in American publishing than in British publishing today.
Do you use the Oxford comma with only two items?
No. The Oxford comma applies only to lists of three or more items. With two items joined by and or or, no comma is needed: write “salt and pepper,” not “salt, and pepper.” A comma before and between two items appears only when it joins two complete independent clauses.