[1] Administratively it belongs to the Northeast Greenland National Park.

The glacier was named by Robert Peary after E. B. Thomas, one of the founding members of the Peary Arctic Club in New York.

It flows northwestwards with its terminus at the head of the Hunt Fjord.

[3] The peaks of the Roosevelt Range close to the head of the Thomas Glacier rise to heights of nearly 1,500 m (4,900 ft).

In the area of its terminus sharp-peaked, dark nunataks protrude above the ice.