The Mute Swan's native range includes most of Europe and Asia, and occasionally winter migration will take it as far south as north Africa.  It has also been introduced and naturalized in North America, southern Africa, and to Australia, New Zealand and their neighboring islands.

Mute swans closely resemble Whooper swans, but can be distinguished from them by the color of their bills (Mute Swans have a reddish-orange bill, while Whooper Swans have yellow bills) and by the fleshy projection on their foreheads just above the bill, which the Whooper Swan lacks.  Swans are among the largest flying birds, and although they are not the longest species, Mute Swans are among the most massive.  A Mute Swan male, or "cob", was the heaviest waterfowl ever recorded, weighing in at 50 pounds (23 kg) in Poland.

Mute Swans, like the rest of the Anatidae family, are herbivores, and their diet consists mainly of aquatic plants.  They form mated pairs within their flock, and mate for life with rare exceptions.  Such splits of previously-mated pairs usually only occur after a failed nesting, and are extremely uncommon.  This lifelong pairing has led them to be used to symboliza love, marital devotion, and loyalty since ancient times.