What is the common name for a legal document that transfers property ownership?

The legal document that transfers property ownership is commonly referred to as a deed. A deed is a formal document that signifies the transfer of title from one party to another. It includes essential details such as the names of the parties involved, a description of the property, and the signature of the grantor (the person transferring the property), thereby serving as evidence of the ownership transfer once it is executed and delivered.

While the other options play significant roles in real estate transactions, they do not specifically refer to the document that transfers ownership. A title represents the legal right or ownership of the property, but it is not actually the document that conveys that ownership. A contract is an agreement between parties, which may involve the sale of property but does not itself transfer ownership. A mortgage is a loan secured by the property, allowing the buyer to borrow funds to purchase the property, but again, it does not facilitate the transfer of ownership. Thus, the deed is the correct answer as it is the primary document used to effectuate the transfer of property ownership.