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Is it Octopi or Octopuses? | Correct Plural of Octopus

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We'll help you learn once and for all which is the correct plural of “octopus.”

Whether octopi or octopuses is the correct plural form of octopus is often debated, and the answer can vary depending on which source you rely on. However, “octopuses” is the preferred and most commonly used plural noun form of “octopus.”

Examples of using octopi or octopuses in a sentence
At the aquarium, we saw several species of octopi/octopuses.

Octopi/octopuses. are incredibly intelligent animals.

I got my nephew color books filled with different types of octopi/octopuses..

Octopi or octopuses

When it comes to “octopi” and “octopuses,” both are considered acceptable, but “octopuses” is the prevalent plural form. 

Octopuses is the preferred plural form of octopus.
Although "octopi" is considered acceptable by some sources, "octopuses" is the more widely used plural form of "octopus."


“Octopi” (pronounced “awk-toe-pie”) has been used as the plural of “octopus” since the 19th century.

In Latin, many words are made plural by replacing “-us” with “-i,” such as “alumnus” and “alumni.” However, “octopus” is not originally derived from Latin. 

“Octopus” was coined by scientists who Latinized the Greek word “oktṓpous” to categorize the animal. This is where the argument arises that “octopus” should follow Latin conventions and therefore be pluralized by replacing “-us” with “i” to form “octopi.” However, those against this position claim that applying this rule to “octopus” is incorrect because it is originally a Greek word. 

Even so, some major authoritative dictionaries, including the Merriam-Webster dictionary, list “octopi” as an acceptable plural form of “octopus.”

Examples: Using octopi as the plural of octopus
We studied and discussed many species of octopi during our marine biology class.

Octopi are fascinating and intelligent creatures.

We accidentally caught several octopi in our fishing net but released them back into the ocean.


“Octopuses” is the most common plural form of “octopus.” It follows typical English conventions in which nouns that end with “-us” are typically pluralized by adding “-es,” such as “bonus” and “bonuses” and “circus” and “circuses.”

Examples: Using octopuses as the plural of octopus
My little brother has a strange fear of octopuses.

Octopuses seem like cool animals because of their eight arms and big brains.

The marine sanctuary is currently rehabilitating numerous octopuses with plans of releasing them.

It’s worth noting that “octopodes” is also sometimes suggested as the correct plural form of “octopus,” based on the belief that because it was derived from a Greek word, it should have a Greek ending. However, “octopodes” is far less common than “octopi” and “octopuses.”

What is the plural of octopus?

If you’re looking for a straightforward answer on which plural form of “octopus” you should use, we’d recommend going with “octopuses.” A Google Ngram search confirms that this is by far the most popular option. 

But don’t worry if you accidentally say “octopi,” as some dictionaries also list this as an acceptable plural form. In other words, using “octopi” as the plural of “octopus” wouldn’t be as egregious as using meese as the plural of moose.

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