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 Alaska, fee simple ownership represents the most comprehensive type of real estate ownership. The owner of a fee simple estate has the right to use the property, sell it, lease it, bequeath it, or otherwise dispose of it as they see fit. However, these rights are subject to certain limitations imposed by law. The government retains the power to levy property taxes on the land and can take the property through eminent domain for public use, provided fair compensation is given to the owner. Additionally, the state's police powers may impose regulations for the general welfare, such as zoning laws and environmental regulations. If a property owner passes away 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 limit its use or the type of structures that can be built on it.