Irwin Glacier (71°7′S163°25′E) is a steep tributary glacier in the Bowers Mountains of Antarctica, draining northeast from Edlin Névé and at the terminus coalescing with Montigny Glacier (from the north), with which it enters the larger Graveson Glacier. The glacier was mapped by the United States Geological Survey from surveys and U.S. Navy air photos, 1960–64, and was named by the Advisory Committee on Antarctic Names for Carlisle S.