Marinelli Glacier is a tidewater glacier located in Alberto de Agostini National Park, Isla Grande de Tierra del Fuego. The glacier spills out from the backbone of the Cordillera Darwin and calves into Ainsworth Bay, an embayment of the Almirantazgo Fjord. The Marinelli Glacier is in a state of retreat, beginning at least as early as 1960 and continuing to the present time.