The Oxford Comma: What It Is and Whether to Use It
1 min read
Short answer
What it is
In a list of three or more items, the Oxford comma is the one before the final and or or.
- With it: We bought bread, cheese, and olives.
- Without it: We bought bread, cheese and olives.
It is also called the serial comma. The name comes from Oxford University Press, whose house style has long used it.
Who uses it
Style guides genuinely disagree, which is why there is no single right answer.
| Usually uses it | Usually leaves it out |
|---|---|
| Chicago Manual of Style | AP Stylebook (most US news) |
| APA and MLA (academic writing) | The Guardian and most UK newspapers |
| Oxford University Press |
If your school, publication or company has a style guide, follow it. If not, pick one approach and use it throughout the document.
When it matters
Most of the time, the meaning is clear either way. But sometimes leaving the comma out creates an ambiguity.
I’d like to thank my parents, Ana and Tom.
Without an Oxford comma, this can read as though Ana and Tom are the parents. With it — my parents, Ana, and Tom — it is clearly a list of four people.
It can also go wrong the other way. I’d like to thank my mother, Ana, and Tom could mean three people, or it could mean the mother is Ana. When a list is ambiguous either way, the fix is to reorder it or rewrite it: I’d like to thank Tom, Ana and my mother.
Lists with longer items
The comma earns its place most clearly when the last two items are long, or when one of them contains and:
The menu offered soup, fish and chips, and apple pie.
Without the final comma — soup, fish and chips and apple pie — the reader has to work out where one dish ends and the next begins.
The practical rule
- If you have a style guide, follow it.
- If you don’t, choose one approach and stay consistent.
- Either way, add the comma — or rewrite the sentence — whenever the list could be misread.