Yes, APA language guidelines state that you should always use the serial comma (aka Oxford comma) in your writing. This means including a comma before the word “and” at the end of a list of three or more items: “spelling, grammar, and punctuation.” Doing this consistently tends to make your lists less ambiguous.

A serial comma is the comma placed before the and or or prior to the final item in a list. It is also known as the Oxford comma and is required in the 7th edition APA style to improve clarity in the writing. (American Psychological Association, 2020, p. 189).

The serial comma, also known as an Oxford comma, appears before the last item in a list of three or more items (American Psychological Association, 2020, p. 155). The 7th edition of the Publication Manual of the American Psychological Association requires authors to include serial commas; see page 155 in the 7th edition manual for information.

The most basic type of list appears in the running text of a sentence, with each item separated by a comma. All lists in APA Style should include a serial comma—the final comma before the conjunction. For example, Each child was given a plush toy, a building block, and a rubber ball.

This week we address the serial comma, seventh in the list of the Top 10 most common APA Style errors as identified by Onwuegbuzie, Combs, Slate, and Frels (2010). Also known as the Oxford comma, the serial comma is the final comma in a list of three items or more, and it is used immediately before and, or, and occasionally nor.