An insulated shipping liner includes a flexible sealed sack having a first layer and second layer sealed together about their outer peripheral edges to form a housing. An insulating layer made from a single sheet of foam material is located within the housing and is configured to be folded such that a first side portion, second side portion and middle portion create a substantially rectangular box form, with the first and second side portions defining opposing sides of the box form, the middle portion defining a bottom of the box form, the substantially rectangular top flap defining at least part of a top of the box form, and the opposing substantially rectangular first and second side flaps defining at least part of other opposing sides of the box form. The box form can be placed in a container to form an insulated container for shipping and/or storage.