Abstract: A backpack cooler (10) designed to be worn on the back of a person includes a flexible enclosure (12) having backpack straps (14) affixed to the enclosure (12). The enclosure includes front, rear, side and bottom walls (18-24) and an openable top panel (26). The walls (18-24) and panel (26) include an outer fabric layer (28), inner foil facing (30) and thermal insulation (32) between the layer (28) and facing (30). A flexible, water-impervious synthetic resin liner (54) is situated within the enclosure (12). The cooler (10) may be equipped with external pockets (58, 60, 67, 72).