南极洲（Antarctica）是地球最南端、位于南极的大洲。它坐落于南半球的南极区，几乎全洲都在南极圈以南，四周环绕着南冰洋。南极洲的土地面积约有1400万平方千米（540万平方英里），是世界上第五大洲，依序位列亚洲、非洲、北美洲和南美洲之后。南极洲约98%面积被冰覆盖，冰的厚度平均达1600米（1.0英里）。

南极洲是地球上最为寒冷、干燥、多风的大洲，也拥有最高的平均海拔。它的沿海和非内陆地区的年降水量只有200毫米（8英寸），因此被视作寒漠。自然环境严酷，整年有一千人暂时居住在大陆上零星的观测站中。只有适应寒冷的植物和动物能生存于此，包括企鹅、海豹、线虫、缓步动物、螨、多种藻类和其他微生物，以及冻原植被。

Antarctica (US English /æntˈɑːrktɪkə/, UK English /ænˈtɑːktɪkə/ or /ænˈtɑːtɪkə/ or /ænˈɑːtɪkə/) is Earth's southernmost continent, containing the geographic South Pole. It is situated in the Antarctic region of the Southern Hemisphere, almost entirely south of the Antarctic Circle, and is surrounded by the Southern Ocean. At 14,000,000 square kilometres (5,400,000 square miles), it is the fifth-largest continent in area after Asia, Africa, North America, and South America. For comparison, Antarctica is nearly twice the size of Australia. About 98% of Antarctica is covered by ice that averages 1.9 km (1.2 mi; 6,200 ft) in thickness, which extends to all but the northernmost reaches of the Antarctic Peninsula.