Octopuses is the standard plural in modern English, and it is the safest choice for everyday writing.
People often say octopi because it sounds like other Latin derived plurals such as cacti or alumni. The twist is that octopus is not originally a Latin word. It comes from Greek, built from roots meaning eight and foot.
If you follow Greek patterns, the plural would be octopodes (pronounced roughly “ok TOP uh deez”). That form is real, but it is uncommon in current English, and many readers find it distracting.
So what should you use?
- Use octopuses in most contexts: We saw three octopuses while snorkeling.
- Expect octopi in casual speech, but know it is a Latin styled back formation.
- Use octopodes only if you are intentionally being etymological or technical, and your audience will recognize it.
In short, octopuses matches normal English plural formation, and it avoids the mismatch between Latin rules and a Greek origin.
