Fonfon Glacier (Bulgarian: ледник Фонфон, romanized: lednik Fonfon, IPA: [ˈlɛdnik fonˈfɔn]) is the 4 km long and 2.3 km wide glacier on the east side of the main crest of north-central Sentinel Range in Ellsworth Mountains, Antarctica.

The glacier drains the northeast slopes of the northern summit of Long Gables Peak and the southeast slopes of Mount Anderson, flows northeastwards and joins upper Ellen Glacier southeast of Eyer Peak.

The glacier is named after the Fonfon locality on Vitosha Mountain, Bulgaria.

This article includes information from the Antarctic Place-names Commission of Bulgaria which is used with permission.

This article about a glacier in Ellsworth Land is a stub.