Fee simple is an ownership interest in real property that is the most full, unlimited, and absolute property interest recognized by law. This ownership interest of title in fee simple is also referred to as fee simple absolute; estate in fee simple; fee simple title; or simply fee, and the term is usually used to indicate the real property ownership interest a seller is transferring to a buyer.

The rights of a fee simple property owner are limited by the government’s power to tax the land (property taxes) and to purchase the land through the compulsory process mandated by state law—often as provided in the state’s constitution or in the state’s statutes—which is known as eminent domain.

In limited circumstances fee simple ownership may also be subject to the state’s police powers, the law of escheat (when the property owner dies without a will and without heirs), and encumbrances or deed restrictions on the use of the land.

In Pennsylvania, fee simple ownership represents the most complete form of ownership in real estate. A fee simple owner has the right to possess, use, and dispose of the property as they see fit, subject to certain limitations. These rights are subject to governmental powers such as taxation, where the government can levy property taxes against the land. Additionally, the government may exercise its power of eminent domain to compel the sale of the property for public use, provided that just compensation is given, as outlined in both the U.S. Constitution and Pennsylvania state law. The state's police powers may also impose limitations on the use of the property for the protection of public health, safety, and welfare. If a fee simple property owner dies intestate (without a will) and without heirs, the property may escheat, or revert, to the state. Lastly, the use of the property may be restricted by encumbrances or deed restrictions, which are conditions placed on the property that bind current and future owners.