It was found by a submersible vehicle at a depth of around 2.5 miles (4km) off Necker Island.
Scientists from the National Oceanic and Atmospheric Administration (NOAA) said it was a depth record for an octopod without fins.
The creature has already been nicknamed "Casper" after the cartoon ghost.
The octopod lacked pigment cells, giving it its light-coloured appearance.
"It is almost certainly an undescribed species" Michael Vecchione of the NOAA said, calling it a "remarkable little octopod".
Deep-sea octopods fall into two categories - cirrate, or 'Dumbo', octopods with fins, or incirrate octopods, without fins, which look more akin to shallow-water octopus.
The sighting of Casper represents the deepest ever observed sighting of an incirrate octopod, Mr Vecchione said.
Scientists say a translucent, "ghost-like" octopod discovered in ocean depths near Hawaii is "almost certainly" a new species.