Giesecke Glacier is a glacier in Avannaata municipality in northwestern Greenland. Its outflow is split in the center by a nunatak. Through two tongues it drains the Greenland ice sheet westwards into Kangerlussuaq Icefjord. The northern tongue reaches the fjord at 73°35′N 55°36′W. The southern tongue reaches the fjord at 73°30′N 55°28′W.