Magellanic Penguins are medium-sized penguins which grow to be 61-76 cm (24-30 in) tall and weigh between 2.7 kg and 6.5 kg (5.9-14.3 lbs), with the males being larger than the females and weight dropping while each parent nurtures its young.Adults have black backs and white stomachs.
There are two black bands between the head and the breast, with the lower band being in an inverted horseshoe shape. The head is black and has a broad white border running from behind the eye, around the black ear-coverts and chin, and joining on the throat. Chicks and juveniles are grey-blue on their backs, with a more faded grey-blue color on their chest.
In the wild, Magellanic Penguins can live up to 25 years, while ages of 30 years have been reached in captivity.
Young birds usually have a blotched pattern on their feet, with this 'blotching' fading as they age. Older birds of over ten years usually have solid black feet. Like the other species of penguins, the Magellanic Penguin has very rigid wings used to 'fly' under water.