What is the technically correct plural of "octopus"?

'Octopuses' is the technically correct and most widely accepted plural of octopus in everyday English, because the word octopus originally comes from Greek rather than Latin, meaning the common Latin-style pluralization pattern used for words like cactus or fungus does not actually apply here in the way people often assume.

'Octopi' assumes octopus follows Latin pluralization rules, but since its root is Greek, that assumed Latin plural does not hold up under strict etymological scrutiny, while the fully Greek-derived plural, octopodes, is technically also valid but is rarely used in everyday speech and sounds unfamiliar to most English speakers.

Many other English words borrowed from Greek face similar pluralization confusion, since English speakers often default to Latin-style endings out of habit, showing how the origins of loanwords can quietly complicate what feels like a simple grammar question.