Landreth Glacier (Bulgarian: ледник Ландрет, ‘Lednik Landreth’ \'led-nik 'lan-dret\) is the steep 2.3 km long and 600 m wide glacier on the southeast side of Imeon Range, Smith Island in the South Shetland Islands, Antarctica, which is draining southeastwards from Mount Foster between the side ridges separating it from Rupite Glacier to the north and Dragoman Glacier to the south, and flowing into Ivan Asen Cove on Bransfield Strait.