What is the Oxford comma also called?

The Oxford comma is also called the serial comma.

It is the comma placed after the next-to-last item in a list of three or more items, before the final conjunction: “France, Italy, and Spain.” Without it, the same list may appear as “France, Italy and Spain.” The term Oxford comma comes from the long-standing house style of Oxford University Press.

“Serial comma” is the broader descriptive name, while “Oxford comma” is one of its best-known regional or institutional labels. “Harvard comma” and “series comma” are also used. The convention is a style choice rather than a universal grammatical rule: many American academic and formal style guides recommend it, while some journalistic and British styles often omit it.

The comma can clarify meaning, especially when list items are complex or could be mistaken for names in apposition. However, it does not solve every ambiguity, and consistency within a document matters more than treating one style as universally correct.