Jeffries Glacier () is a glacier between Lenton Bluff and Maro Cliffs, flowing northwest for at least 8 nautical miles (15 km) through the Theron Mountains. First mapped in 1956-57 by the Commonwealth Trans-Antarctic Expedition and named for Peter H. Jeffries, meteorologist with the advance party of the Commonwealth Trans-Antarctic Expedition in 1955-56.
It should not be confused with the Jeffryes Glacier.
This article incorporates public domain material from the United States Geological Survey document "Jeffries Glacier" (content from the Geographic Names Information System).