Video of the incident, taken by staff members at a salmon farm on Vancouver Island, shows the bird floating on the surface of the water, its wings spread, with the tentacles of what appears to be a giant Pacific octopus wrapped around it, apparently trying to drown it.
The video shows staff using a pole to lift the octopus off of the eagle.
In a Facebook post, Mowi Canada West farm, whose staff saved the eagle, said the octopus swam away unharmed after the encounter, while the eagle recovered on a nearby branch for around 10 minutes before flying away.
"The eagle that had bitten off more than it could chew when it tried to catch an octopus," the post said.
Bald eagles were on the brink of extinction in the late 20th century until the federal government listed it on the Endangered Species Act.