Blood money is money that has been gained from the death of another.

It is used to refer to money paid to the killer (as payment or as a reward after the fact), the money paid to person responsible for betraying them (enabling the killer) or the money paid to the surviving family to make restitution.

Such money is usually considered tainted and won't be accepted if it is known to be "blood money". Parties unrelated (to the death) who obtain blood money unwittingly (as a gift or payment) will often "throw the money at the feet" of the party that gave it to them. This action signifies the unrelated parties' unwillingness to share in the guilt and the desire to return any such guilt back upon the offending party.

Traditionally, people who have accepted blood money will later feel guilty and attempt to either give the money back or give it away in an attempt to absolve themselves. Often even the party responsible for paying out the blood money will consider it tainted and not accept back.

Money paid in restitution isn't considered as tainted as money paid in furtherance of the killing, but some families consider it a matter of pride not to accept such money. Usually this arises from considering the offense unforgivable and the family not willing to have anything to do with the offender.

In Islamic and Arab traditions, blood money is the money paid by the killer or his family or tribe to the family or the tribe of the victim (compare weregild and główczyzna). The tradition has found its way into some of the Islamic countries legislations, including Iran.

In Iran, the Judiciary system announces a table of the amounts each year, with variations based on the month in the Islamic calendar, and the gender of the victim. Generally, in the four haraam months, where wars and killings has been discouraged traditionally in the Arabian peninsula and then the Islamic world, the blood money is doubled, while for female victims, it is halved. Originally, families of religious minorities also received half the usual amount, but that was changed in a legislation in early 2004, which was rejected by the Guardian Council but was finally approved by the Expediency Discernment Council.