The Antarctic Sound (Danish: Antarctic Sund) is a sound in King Christian X Land, Northeast Greenland. Administratively it is part of the Northeast Greenland National Park zone.

The sound was named by Alfred Gabriel Nathorst after his ship Antarctic, on which he found and first mapped this fjord branch in 1899 during the Swedish Greenland Expedition in search of survivors of S. A. Andrée's Arctic balloon expedition of 1897.

It is a fjord forming a channel that runs roughly from northwest to southeast between the southern shore of mid Kaiser Franz Joseph Fjord to the north and the head of King Oscar Fjord to the south. Its minimum width is 3 km.

The Antarctic Sound separates the northeastern shore of Suess Land —part of the Greenland mainland— from the southwestern shore of Ymer Island. Ruth Island lies off the southeastern mouth of the sound.

• List of fjords of Greenland

• Niviarsiat, NE Greenland

• Media related to Antarctic Sund at Wikimedia Commons
• Explanatory notes to the Geological map of Greenland
• Antarctic Sund, Eastern Greenland - 28.8.10
• Massive iceberg, Antarctic Sund, Eastern Greenland - 28.8.10