An assignment is a legal term used in the context of the law of contract and of property. In both instances, assignment is the process whereby a person, the assignor, transfers rights or benefits to another, the assignee. An assignment may not transfer a duty, burden or detriment without the express agreement of the assignee. The right or benefit being assigned may be a gift (such as a waiver) or it may be paid for with a contractual consideration such as money.

The rights may be vested or contingent, and may include an equitable interest. Mortgages and loans are relatively straightforward and amenable to assignment. An assignor may assign rights, such as a mortgage note issued by a third party borrower, and this would require the latter to make repayments to the assignee.

A related concept of assignment is novation wherein, by agreement with all parties, one contracting party is replaced by a new party. While novation requires the consent of all parties, assignment needs no consent from other non-assigning parties. However, in the case of assignment, the consent of the non-assigning party may be required by a contractual provision.