A little blue penguin was spotted in central Christchurch today after making its way up the Avon River.

The Department of Conservation received calls about the penguin from contractors working on the Canterbury Earthquake National Memorial on Oxford Tce, Fairfax reported.

Ranger Jenna Thoms said the penguin seemed happy and healthy.

"[He's] just swimming up and down some rapids, doing some fishing. So, at this stage, we're just going to leave him alone," she told Fairfax.

The penguin's presence so far from the Avon Estuary, several kilometres away, was "slightly unusual" but not unheard of.

Thoms urged people to keep their distance and make sure dogs were on leashes.