In archaeology, a biofact or ecofact is an object, found at an archaeological site and carrying archaeological significance, but (unlike an artifact) not altered by human hands.

A common type of biofact is a plant seed. A seed can be linked to the species of plant that produced it; if large numbers of seeds of an edible species are found at a site, it may be inferred that that species was being grown for food there. Another type of biofact is an (uncarved) wooden roof beam. Dendrochronological analysis of some wood samples can help to determine the date during which a site was occupied.