Nemo dat quod non habet, literally meaning "no one [can] give what they don't have" is a legal rule, sometimes called the nemo dat rule that states that the purchase of a possession from someone who has no ownership right to it also denies the purchaser any ownership title. This rule usually stays valid even if the purchaser does not know that the seller has no right to claim ownership of the object of the transaction (bona fide).

This rule applies generally in situations such as the Holocaust reconciliation movement in which property, such as pieces of art, that was stolen or confiscated by the Nazis is returned to the families of those it was taken from. Anyone who purchased the art or thought they had ownership are denied any rights over the litigious property due to the nemo dat rule.