The first humpback whale of the season has been spotted in Akaroa Harbour.

Akaroa Dolphins posted video of the sighting near Akaroa township to its Facebook page on Saturday.

"With the great humpback migration now in full swing, we were treated to an exciting surprise - our first humpback sighting of the season right down the harbour near Akaroa’s township," the post said.

"It’s incredibly rare to see a humpback this far in, so we suspect this may have been a curious young juvenile exploring the area.

"Our last sighting had it heading back out toward the harbour entrance.

"What an incredible reminder of the wild beauty right on our doorstep."