Arctic char or Arctic charr (Salvelinus alpinus) is both a freshwater and saltwater fish in the Salmonidae family, native to Arctic, sub-Arctic and alpine lakes and coastal waters. No other freshwater fish is found as far north. It is the only species of fish in Lake Hazen, on Ellesmere Island in the Canadian Arctic. It is one of the rarest fish species in Britain, found only in deep, cold, glacial lakes, mostly in Scotland, and is at risk from acidification. It is also found in deep mountain lakes in England, Ireland and Wales. In other parts of its range, such as Scandinavia, it is much more common, and is fished extensively. It is also common in the Alps, (particularly in Trentino and in the mountain part of Lombardy), where it can be found in lakes up to an altitude of 2,600 m (8,500 ft). In Siberia, it is known as golets (from the Russian голец) and it has been introduced in lakes where it sometimes threatens less hardy endemic species, like the long-finned char.
The Arctic char is closely related to both salmon and trout and has many characteristics of both. Individual char fish can weigh 20 lb (9.1 kg) or more with record sized fish having been taken by angling in northern Canada, where it is known as iqaluk or tariungmiutaq in Inuktitut. Generally, whole market sized fish are between 2 and 5 lb (0.91 and 2.3 kg). The flesh colour of char varies; it can range from a bright red to a pale pink.