Alert is the northernmost permanently inhabited place in the world. It is located at , about 10 km west of Cape Sheridan, the northeastern tip of Ellesmere Island, on the shore of ice-covered Lincoln Sea, in the territory of Nunavut in Canada. Alert lies just 817 km (507 mi) from the north pole.

Alert had 5 permanent inhabitants in the 2001 census. Alert also has many temporary inhabitants as it hosts a military signals intelligence radio receiving facility at Canadian Forces Station Alert (CFS Alert), as well as a co-located Environment Canada weather station, a GAW atmosphere monitoring laboratory, and the Alert Airport.

The rugged terrain of the settlement is surrounded by hills and valleys. The shore is composed primarily of slate and shale, and the sea is covered with pack ice year-round. The local climate is actually semi-arid. However, evaporation rates are also very low, as average monthly temperatures are above freezing only in July and August. There is 24-hour daylight from the last week of March until the middle of September and the sun is above the horizon from mid-April through August. From mid-October through the end of February the sun does not rise above the horizon and there is 24-hour darkness from the end of October until mid-February.